Glossary

Every week, I update this glossary letter by letter to explain medical/scientific topics to children.

A

Allergy

The body has a strong army called the immune system. It protects you from real bad guys like germs. But sometimes, this army gets confused and sees something harmless, like dust or pollen, as a big enemy. So it launches an attack. This overreaction is called an allergy, and it can cause sneezing, itchy skin, red eyes, tummy troubles, or trouble breathing.

Anemia

Our body has special agents called red blood cells that deliver oxygen, like little trucks. When there are not enough or they do not work well, the body does not get enough oxygen. This is called anemia, and it can make you feel weak, tired, or short of breath, like dancing with your shoelaces tied together!

Antibiotics

When bad invaders called bacteria enter our body, they can make us sick. Our immune army fights hard to kick them out, but sometimes it needs a little help. That is when we use antibiotics—special medicines that help remove the bad bacteria. They are like backup heroes joining the battle to help you feel better!

Asthma:

The lungs are like a tree, full of branches. But asthma happens, the tiny branches inside get swollen and filled with sticky mucus. That makes it hard for air to pass through, like a blocked path in the forest.

Autism

Our brain is a super powerful tool filled with stars called neurons. These stars connect and form different constellations. Autism happens when the brain builds a unique constellation, which means it works in a different way. This can affect how someone talks, plays, or interacts with others. Autism is not a disease. It is a special way to be.

B

Bronchitis

Our body has an airway system that helps us breathe, and it looks like a tree with tiny branches called bronchioles. Bronchitis happens when tiny villains, germs, attack these little branches, making them sick, red, and swollen. Our body tries to fight back and makes a sticky liquid, kind of like condensed milk. But too much of this “condensed milk” makes us cough a lot!

Burns

When we touch something very hot, like a stove, or even something very cold, like ice for too long, our skin can get hurt. That’s called a burn. Imagine your mom or dad cooking a piece of meat — first the color changes, then it turns red or brown, and sometimes a little juice comes out. Burns on our skin can look red, swollen, or even form bubbles. But unlike dinner, burns hurt a lot, and our skin needs special care to heal and feel better again

Broken bone

Our bones are very strong, but if we fall badly or something hits us very hard, a bone can break. Imagine you are playing with your favorite toy and accidentally throw it — it might break into pieces! The same thing can happen with our bones. When a bone breaks, it takes time and care to heal. Doctors use special armor, like a hard plaster shell, to keep the bone pieces still and safe. This way, they can grow back together and become strong again.

Bleeding

Our body has a special liquid called blood. Blood is very important because it carries nutrients, oxygen, and other good things all around our body. When we get a cut, the blood comes out, kind of like when you bite into a juicy strawberry and the juice spills out! But we do not want to lose too much blood. That is why we need to press on the cut to stop the bleeding. If it is too big, we need to go see a doctor to help us to heal.

Bacteria

C

Cancer
Imagine your body is a garden, full of strong, beautiful plants and flowers — these are your cells. Tiny garden helpers (called genes) take care of them, helping them to grow healthy. But sometimes, the helpers do not work well. Then, some plants start growing wild and fast, like weeds.  This is called cancer.

Chicken Pox
This illness is caused by teeny-tiny germs (a virus). It covers your skin with red, itchy blisters — like little red chicken peas. It is very contagious, which means it spreads easily to other kids and family. To get better, you need to get rest and stay at home.

Cleft Lip
A cleft lip is when there is a small space in the upper lip. It happens while a baby is growing in the mommy’s belly. Doctors can do surgery to help fix the gap so the baby can eat, smile, and grow happy and healthy.

Caries (Tooth Decay)
Caries are sneaky villains (bacteria) that attack your teeth. They love sugar and will start making holes if you do not brush your teeth well. First, they leave white stains. Then they start biting into your teeth, which can hurt.

A dentist can help kick out the bacteria and repair the teeth, turning them into new ones again.

Conjunctivitis (Pinkeye)
This is when your eye gets pink, itchy, and not so pretty. This happens because tiny germs enter your eye and make you feel like a grain of sand is stuck in it.

Sometimes pinkeye gets better after a few days. But some kids need magical eye drops to make it back the normal.

D

Diabetes

Diabetes is when the sugar (called glucose) in the blood is too high.
Our cells need glucose to get energy and work well—just like your toy needs a battery to run.
But glucose cannot get into the cells all by itself. It needs a special car to carry it from blood into cells.

In diabetes, this car has problems. So the sugar stays stuck in the blood, and the cells don’t get all the energy they need to work well.

Deaf

A Deaf person is someone who doesn’t hear the same way other people do.

Imagine your ear like a tunnel with tiny special machines inside (called ossicles) that help the sound get louder. Sound travels into the ear like waves, touches those little machines, and helps you hear.

But sometimes, there are obstacles in the tunnel—or the machines don’t work quite right—so the sound doesn’t go through as it should. That’s when a person may not hear well, or may not hear anything at all.

Some Deaf people use sign language to talk with their hands. That’s an awesome way to communicate, too!

DNA
Our body has its own special language called genetic information.
Every part of the body has a little book written in this language, and that book is called DNA.

DNA looks like a twisting ladder, and it gives instructions that help our cells work well —and help make each person who they are.

Everyone’s DNA is a little different. That is why each person is unique, like a own adventure story.

Dermatitis

Our skin works like bricks in the wall, together protecting the skin from damage. But when something irritates the skin, making the bricks a bit more separated, you can feel rash, redness, swallowing. This we call dermatitis.

Down Syndrome

Remember how our body has special books called DNA?
These books are grouped together into bigger packages called chromosomes—like shelves in a big library.

Most people have 46 chromosomes, organized in pairs. But in Down Syndrome, a baby is born with one extra chromosome. That means there is one shelf with three books instead of two!

This extra set of instructions can affect how the body and brain grow. People with Down Syndrome may have certain features, like a flatter face or eyes that tilt upward, and they might learn more slowly or need extra medical care, like help with their heart.

But just like everyone else, they have their own special story, filled with smiles, talents, and love.

Dermatitis

Your skin is like a wall made of tiny bricks, all stacked together to protect your body. But sometimes, something irritates the skin—like a strong soap, a bug bite, or even the weather. This can make the bricks spread apart a little, and the skin gets red, itchy, swollen, or bumpy. That is called dermatitis—a kind of rash that means the skin needs some extra care to heal and feel strong again.

E

Edema

Imagine your body is filled with pipes—big ones and tiny ones—carrying liquid (called fluid) to all the places it needs to go (from your toes to your head).

Now, when something bothers your body, like a bug bite, a sunburn, or when you have some type of disease, some of those tiny pipes can start to leak. That leak causes fluid to build up under your skin, like a little water balloon. That is called edema.

Emergency

An emergency happens when someone suddenly gets very sick or hurt, like breaking a leg while playing soccer.

The emergency room is a special part of the hospital made for kids and adults who need quick help. Doctors and nurses in the emergency room check you carefully and treat you fast so you can get better sooner.

Epilepsy

Your brain is made of many tiny cells. These cells send electrical signals to each other, like Christmas lights turning on and off.

But sometimes, some of the brain cells do not connect the right way. This causes mixed-up signals, like a short circuit in the lights. That is called epilepsy.

When it happens, the body might start to shake or move uncontrollably. This is called a seizure. Doctors can help treat epilepsy so kids with it can feel safe and strong.

Emotions

Everyone has emotions. They are the feelings that live inside you.

Sometimes you feel happy, like when you play with a friend. Sometimes you feel sad, like when you lose your favorite toy. You might feel angry when something feels unfair,
Emotions help you understand what is happening around you and inside you. All emotions are important. They are part of being a human being, like you.

Esophagus and Esophagitis

When you eat or drink, the food goes from your throat to your stomach through a long pipe inside your body. This pipe is called the esophagus. It moves food and drinks down, so your stomach can break them into tiny, tiny pieces.

But sometimes, something weird happens. Tiny bugs (germs) might bother your body, or there might be too much acid in your stomach.

When that happens, the esophagus gets swollen and red. And you can feel pain or like something is burning inside you. This is called esophagitis.

F

Fever

When tiny villains (germs) sneak into your body, your body’s superhero team, the immune system, turns up the heat to fight them off. This extra heat is called a fever. You might feel hot for one minute and cold the next. That is just your body working hard to protect you and chase germs away.

Fungal infection

Have you ever seen fuzzy, weird-colored spots on old bread? That’s called fungus. Some types of fungus can enter our bodies, especially our skin, nails, and sometimes other places. When that happens, it is called a fungal infection.

Special creams and medicines can help kick the fungus out and make you feel better again.

Flu

The flu happens when a very tiny germ invades your body. It sneaks in through your respiratory system, like a set of pipes carrying air to your lungs. This tiny villain damages parts of that system, causing fever, chills, body aches, cough, headache, sore throat, and tiredness. Sometimes, it even gives you a bellyache and makes you feel like throwing up.

Fainting

Imagine your body is like a plumbing system, with pipes that carry blood everywhere, especially to your brain, which is a super important control center. Sometimes, if not enough blood gets to the brain, your body feels weak, dizzy, and suddenly everything goes black—like your body presses a quick “pause” button. This is called fainting. Usually, it lasts just a few seconds, and your body wakes up once the blood flows back to normal again!

Food Poisoning

When you eat food that has sneaky germs hiding in it, those germs can get inside your tummy and make you feel sick. You might get a bellyache or even feel like throwing up. That is called food poisoning.

G

Gingivitis

Our gums, the pink part that hugs our teeth, help keep them in place. When we eat food, especially our favorite candies, and forget to brush and floss our teeth, tiny villains (bacteria) enter the gum. They make the gums red and puffy, like red balloons. This is called gingivitis.

Genes

Remember how every part of your body has a little book written in a special language? That book is called DNA. Each chapter of that book is called a gene. Genes carry important instructions, like what color your eyes and hair will be, how tall you might grow, and other cool things about your body. They help build and guide how your body grows and works.

Gastritis

After you eat, food travels from your mouth to your stomach. Your stomach has a special lining called the mucosa, like a protective sticker that protects your toy from getting scratched. But sometimes, certain medicines or germs can damage that sticker. When that happens, the stomach gets irritated, and that is called gastritis. It can give you a stomachache, make you feel sick, or even make you throw up.

Germs

Germs are tiny creatures so small you need a microscope to see them. Some germs are like little villains that sneak into your body and try to make you sick.

GERD

GERD (short for Gastroesophageal Reflux Disease) happens when food and stomach juice—more sour than a lemon!—travel back up into the esophagus, the tube that connects your mouth to your stomach. It is kind of like when you press a balloon filled with water, and the water sloshes up and down. GERD can cause more hiccups than usual, belly aches, nausea, throwing up, and a hot, burning feeling in your chest called heartburn.

H

Hormones

Hormones are like tiny mail carriers your body makes.
They travel all around, delivering special messages to help everything run perfectly, like telling your body when to grow, sleep, or even feel hungry.
It is like your body has a secret post office, and hormones are the mail that keeps everything on track.

Hemophilia

Our blood travels through the body like cars on a highway. When we get a cut, our body needs to stop bleeding, like cars using brakes after an accident. But in hemophilia, the brakes (called clotting factors) don’t work well. That means the bleeding doesn’t stop easily, and someone can lose too much blood.
Doctors can help by giving those missing clotting factors, like fixing the brakes, so everything works well again.

Headache

You know when your head starts hurting? That is called a headache. Imagine you had a balloon filled with too much air and needed to empty it a little bit.  The same happens in your head, especially when you’re tired, hungry, feeling sick, or looking at a screen too long.
Taking a break, drinking water, or getting some sleep can help your head feel better again.

Hematoma

Have you ever seen a big purple spot on your skin after a fall or bump? That’s called a hematoma.
Your body has a plumbing system made of tiny pipes (called blood vessels) that carry blood everywhere. When you fall or hit something hard, those tiny pipes can break, and blood leaks under the skin, like a little puddle. That is why it looks purple or blue.
It usually goes away on its own as your body slowly cleans it.

HIV

HIV (immunodeficiency virus) is a tiny, tiny villain that attacks your body’s army, destroying the soldiers on the front line (immune cells). Because of this, your body cannot protect itself from other invaders and diseases, and it becomes weak. HIV leads to a disease called AIDS (acquired immunodeficiency syndrome).

I

Insulin

Insulin works like a special car that carries sugar (glucose) from the blood into your cells. All cells need sugar to get energy and do their jobs—just like cars need fuel to run.

This special car is made in a factory inside your body called the pancreas. Insulin controls how much sugar stays in your blood and how much it goes into your cells.

When there isn’t enough insulin, sugar stays in the blood, and the cells don’t get the energy they need. That’s why some people with diabetes need extra insulin, to help the sugar reach the right place.

Immune system

The immune system is like your body’s army. It works day and night to protect you from invaders, like tiny, tiny villains called germs.

These villains can be viruses, bacteria, or other bad guests that try to make you sick. But don’t worry, your immune system has soldiers that know how to find and fight them. Thanks to this army, your body stays strong, healthy, and ready to fight back whenever trouble arises.

Infection

When tiny villains called germs enter our body, they start to multiply and cause an infection.

As these invaders spread, they can create a nasty yellow or green liquid called pus. Our army (immune system) fights against the germs to chase them away. Sometimes, this battle can make you feel tired or give you a fever.

To help kick the germs out faster, doctors may give you special medicines called antibiotics. Then all you need to do is rest and let your body do its job.

Inflammation

Remember your body’s army—the immune system? It is always on guard to protect you from injuries (like when you get a cut or a bump) and invaders (like germs).

When something goes wrong, you might notice the area gets red, warm, swollen, and painful. This is your army trying to protect and start the healing process. This reaction is called inflammation.

Inflammatory bowel disease (IBD)

The part of your body that helps break the food you eat into smaller pieces is called the gastrointestinal system. A big part of this system is the bowel (or gut), which turns the food you eat into poop, kind of like a blender turning fruit into a smoothie.

But when someone has Inflammatory Bowel Disease (IBD), their guts become sore and swollen. This can cause bellyaches, diarrhea, and sometimes even blood in the poop when going to the bathroom.

Doctors still do not know what makes the gut sick, and there is no cure. But with medicines, healthy foods, fruits, and vegetables, and doctors’ care, people with IBD can feel much better.

J

Joints

Joints make moving, bending, dancing, and playing possible! They are special spots where two bones meet, like your knees, elbows, and fingers. Joints have different shapes and sizes, each helping your body move. It is like your favorite toy that can bend its “knee” or wave its “arm”, only because they have “joints”.

Jaundice

Jaundice is when the skin and the white part of the eyes turn yellow. Sometimes, places like the mouth and nose can look a little yellow, too! This happens when the liver—a special organ that helps clean harmful substances from your body—needs some extra help. It is like the liver is a command center, releasing yellow ink as a signal: “Hey! I need some backup here!”

Doctors can give special medicines to help “wash away” the yellow color and get everything working well again.

Juvenile Idiopathic arthritis

Remember the joints? They have a special protective lining called synovium and a liquid called synovial fluid that helps joints move smoothly.

Sometimes, the immune system—our body’s army—gets confused and sends the wrong commands, attacking the joints by mistake. This makes the synovium produce too much fluid, turning the joints swollen, stiff, and painful. It is like having a little balloon filled with too much water inside the joint, making it hard and sore to move.

Jaw

You know that part that moves when you open your mouth? That is called Jaw. The jaw is a super-strong bone that helps you chew your food, talk, and make funny faces. It is like the Iron Man of your mouth—tough, powerful, and always ready for action!

Jet Lag

Our body has a special internal clock called the circadian rhythm. This clock tells us when it is time to sleep and when it is time to wake up.

But when you travel far, far away—like to another country with a very different time zone—your internal clock gets confused. You might feel awake at night and super sleepy during the day. But don’t worry! After a few days, your clock adjusts, and you will feel back to normal.

K

Kidney

The kidneys are a pair of organs in a bean shape that work as a special filter for your blood. They clean out everything your body doesn’t need, like extra water and waste, and turn it into pee. It is kind of like a filter for water or coffee. They keep the good stuff and throw away the dirty.

Keloid

Have you ever had a cut that turned into a scar?
Sometimes, in some people, the scar doesn’t stop growing—it gets bigger, thicker, and sticks up like a little mountain on the skin.
That’s called a keloid. It is just your body working hard to heal!

Kidney stones

Remember how your kidneys filter out the waste and make pee?
Well, sometimes there is too much of a certain stuff—called calcium—and the kidneys can’t get rid of it all. That extra stuff can stick together and form tiny crystals.
The crystals build up, like when you press little pieces of modeling clay into one big ball.

That’s a kidney stone. Kidney stones can be very painful, cause bleeding, and block pee, but doctors know how to remove these little troublemakers.

Kawasaki Disease

Your body has tiny tubes called blood vessels that carry blood everywhere, kind of like a water pipe system.
Sometimes, in a rare condition called Kawasaki disease, those vessels get swollen and inflamed. The body heats up with a fever that lasts more than 5 days.
Kids with Kawasaki disease might also have red or pink eyes, a red or cracked tongue, and swollen hands or feet.
It sounds scary, but doctors know how to treat it and help kids feel better soon.

L

Lactose intolerance

Our body, mainly the gut, breaks down all the food we eat into small pieces, like a blender processing everything. With milk, cheese, and yogurt, it’s the same.

But there is a special helper that breaks down lactose (a type of sugar found in milk) into tiny pieces. This helper is an enzyme called lactase. It works like a pair of scissors that cuts a paper foil into little bits.

Some people don’t have this help, or it doesn’t work well. Then, they develop lactose intolerance. They can feel sick, with a bellyache, nausea, and diarrhea. To feel better when eating their favorite milk products, they can take medicine with extra helpers (lactase or choose lactose-free food).

Liver

The liver is a super-powerful organ in our body.
It has so many functions, like a 1000-in-1 machine!

One of its main jobs is called metabolism.
That means it helps filter bad stuff from the blood and supports the body in getting rid of it.

The liver is like a superhero cleaner, working behind the scenes to keep everything running smoothly.

Leukemia

Our blood has 3 types of cells:
🔴 Red blood cells, which carry oxygen.
⚪ White blood cells, which are our body’s army.
🟡 Platelets, which help stop bleeding.

All these cells are made in a special machine inside our bones, called bone marrow.

Sometimes, the DNA (our body’s instruction book) sends the wrong recipe.
Then, the body starts making weird cells called leukemia cells. These cells grow very fast and can take over the bone marrow, pushing out healthy cells.

This disease is called leukemia, and it is a type of blood cancer.
There are different types of leukemia, and doctors treat each type in a special way. One of the treatments is changing the special machine, which is called a bone marrow transplant.

Lymph nodes

Lymph nodes are bean-shaped filters in our body that catch bad villains—like germs, foreign substances, and damaged cells. These filters have special zoom lenses that spot invaders and kick them out. The soldiers that do this are called lymphocytes.

Sometimes, you can feel your lymph nodes swollen in your neck when you have a sore throat. That means your body is working hard to clean everything up!

Ligaments

Ligaments help you bend your arms and legs. That way, you can play, dance, walk, run, and do lots of fun things!

Ligaments work like strong and stretchy bands that hold bones together.
They also help keep important parts in your joints in the right place.

M

Meningitis

Imagine your brain like an orange: it has a peel and a soft white layer just under the peel. That thin layer protects the fruit.

Your brain has a similar protective layer called the meninges. It wraps around your brain and spinal cord to keep them safe from harmful invaders.

But sometimes, a bad villain, like a germ, sneaks in and attacks the meninges. When that happens, the layer gets swollen and inflamed. That is called meningitis.

Meningitis can cause fever, headaches, nausea, confusion, and a stiff neck. It is serious, but doctors know how to treat it.

Measles

A tiny, tiny villain (a type of virus) can attack your body and cause measles. It can make you feel really sick, with high fever, a rash, a cough, and red eyes.

Measles spreads super fast from one person to another. That is why kids with measles need to stay home or go to the hospital and follow the doctor’s treatment.

But here is the good news: there is a vaccine that protects kids and grown-ups from measles. So the villain can’t win!

Migraine

A migraine is a really strong kind of headache.
It can feel like something is pounding your head, almost like when you bump your Superman toy too hard!

You might feel dizzy, want to throw up, and feel bothered by light, noise, or even strong smells. Because of that, many people with migraines just want to lie down in a quiet, dark room.

But don’t worry! There are special medicines that can help the pain go away.

Malocclusion

Do you know how LEGO pieces fit together just right?
Our teeth do the same thing. When we close our mouths, they come together in the right spot.

But sometimes, the teeth don’t fit quite right. That is called malocclusion.

It can make biting or chewing harder than normal.
But don’t worry!  Dentists can help fix it with braces that gently move the teeth to the right place!

Myopia

You know when it rains and water drops cover the window?
You can see the drops very clearly, but everything outside looks blurry.

Some people’s vision works kind of like that.
They can see very well close things, like a toy in their hands. But things far away, like toys on a store shelf, look fuzzy and blurry. This is called myopia, or nearsightedness.
To see better, people can wear glasses or contact lenses.

N

Nerves

Imagine the electricity in your house. It works because cables carry energy from the power station to your lights, TV, and fridge.

Your body works in a similar way!
The nerves are like those cables, and your brain is the power station.

Even though you can’t see them, nerves run all through your body. They carry tiny electrical signals that help you:
✨ Feel things
💪 Move your muscles
😮‍💨 Breathe, sweat, and digest food

Nerves help your brain talk to your body, and your body talk back.

Neuropathy

Remember how nerves are like cables that carry electricity in your body?
Neuropathy happens when those cables get damaged.

It’s like when the wires in your house don’t work well. They might give tiny shocks, stop sending signals, or even shut things down.

Infections (tiny germ attacks), some medicines, hard hits (like a strong bump on your leg), or certain diseases can hurt the nerves and cause neuropathy.

People with neuropathy may feel:
⚡ Sharp pain or tiny shocks
😵 Numbness or tingling
💤 Weakness or even trouble moving

Neurons

The electrical circuit of your body works thanks to tiny cells called neurons.

Neurons are a part of the nerves, brain, and spinal cord, and they work together to carry messages all over your body.

Each neuron talks to the others through special connections called synapses.
For this talk, they use a secret language made of tiny electrical and chemical signals.

Every synapse helps control something important, like thinking, eating, moving your arms, and so much more!

Non-Alcoholic Fatty Liver Disease

Remember the liver?
The amazing 1000-in-1 machine that cleans your body and turns food into energy?

Well, the liver also helps clear fat. But sometimes, there’s too much fat, and the liver can’t keep it. Instead of turning it into energy, the fat starts to pile up, like a big fat storage inside the liver.

Over time, that fat can start to hurt the liver. It may get inflamed, swollen, and stop working properly. That is when NAFLD (Non-Alcoholic Fatty Liver Disease) happens.

People with NAFLD (Non-Alcoholic Fatty Liver Disease) may have:
🤢 Belly pain
😟 Yellow eyes and skin
😴 No appetite
😮 A growing belly

That’s why it’s important to take care of our liver and watch the food we eat, so this superhero machine can keep doing its job!

Nausea

Nausea is that bad feeling when it seems like food is coming back up your throat, like you’re about to throw up.

Nausea isn’t a disease, but it might be a way for your body to tell you:
 “Hey! Something is wrong in here!”

It can happen for many reasons, like when you are sick, anxious, or even riding in a car or boat.

O

Obesity

Obesity is when someone has too much fat stored in their body. Over time, that extra fat can affect important organs like the heart, liver, and kidneys — and even lead to problems like type 2 diabetes.

But obesity isn’t just about eating too much. It’s a real disease, and it can be hard to control without help. Kids and grown-ups who live with obesity often need support to build healthy habits — like eating more fruits and veggies, moving their bodies with fun exercises, and taking care of their emotions.

Sometimes, doctors might also give special medicines to help control hunger and support the body’s balance. The most important thing? No one should feel ashamed. Everyone deserves kindness, support, and care.

Otitis media

Our ears help us hear the world around us: music, laughter, voices, and more!

Inside the ear, there are many tiny parts. One of them is called the eardrum — a small, round piece that separates the outer ear from the middle ear.

Sometimes, germs get into the middle ear, behind the eardrum. This can cause an infection called otitis media. The germs build up fluid or pus, which presses on the eardrum.

That pressure can hurt a lot! It’s a bit like filling a balloon with too much water. As the water stretches the balloon, it feels tight and might even burst. That’s similar to the pressure and pain someone feels during an ear infection.

Osteoarthritis

Do you remember the joints? They’re the special spots where two bones meet, like in your knees, hips, or fingers.

To keep bones from rubbing and getting hurt, joints have a soft protective layer called cartilage. Cartilage is like a sneaker: it cushions and protects your bones, just like sneakers protect your feet when you run or jump.

In osteoarthritis, this cartilage gets worn down or damaged. Without that cushion, the bones start to rub together, and that causes pain.

It’s like playing on hard stone ground with old, damaged sneakers, or none at all.

Ouch! Just like your feet would hurt, your joints would hurt when the bones rub without protection.

Osteoporosis

Our bones are usually strong and thick — we call that being dense. They help hold up our bodies, just like strong tree trunks keep a tree standing tall.

But in osteoporosis, bones become thin and weak, and they can break more easily. It’s a bit like an old tree — its branches get so fragile that they can snap with just your hands.

Osteoporosis happens more often in older people, like grandmas and grandpas. But don’t worry! Doctors can help!

They might recommend medicine, vitamins, and exercise to keep bones stronger and safer.

Otalgia

Remember how important our ears are?
Just like any part of the body, the ears can hurt too. When someone has ear pain or an earache, doctors call it otalgia.

There are many reasons for otalgia. It can happen when:
👂 You have an ear infection (like otitis)
🟠 There’s too much earwax
✈️ You’re on an airplane, and the pressure changes
💧Water gets into your ear while swimming
🦷 Or even when you have a toothache. Sometimes the pain spreads to your ear!

The good news? With medicine and a doctor’s help, the pain usually goes away quickly.

P

Periodontitis

Do you know our teeth? They are placed inside the bones in a specific spot, like a key in a locker. To help the teeth stay in place, there’s a stretchy cord called the periodontal ligament. This ligament works like a cushion, absorbing the impact when you bite something hard.

Together, the bone, root of the tooth, and periodontal ligament form the periodontium—the tooth’s special home. But if you don’t floss your teeth for a long time, and you get bleeding and hard plaque (tartar), tiny villains (germs) can sneak into this home and make a mess. The area around the tooth becomes inflamed, swollen, and smelly. Over time, the “cord” gets weak and can’t hold the tooth anymore… and the tooth starts to wiggle! This is called periodontitis.

Pain

You know when you hurt yourself and then you feel… Pain?!

Pain is like a fire alarm in your body. When something is wrong, the alarm rings, and you feel that bad sensation.

If you have a lot of pain and don’t know why, it’s your body’s way of saying, “Hey, we need a detective here!” Doctors are the best detectives! They can find out what’s wrong and help take care of you.

Polio

Polio happens when a tiny germ called poliovirus sneaks into your body and makes your throat and gut sick. You may think it’s the flu, but it’s not.

If that tiny villain reaches your brain or spine, it can mess up your nervous system—the part that controls movement—making it hard or even impossible for kids to walk.
It’s like a car brake: the germ presses the brake and sometimes never lets go.

But don’t worry! We have special shots called vaccines that protect our bodies from this terrible germ.

Pneumonia

Remember your lungs? Those special machines that help you breathe.
They have branches like a tree that bring in good air and push out the bad.

Sometimes, sneaky germs (bacteria, viruses, or fungi) can get inside the lungs. They cause swelling and fill the lungs with liquid. That’s called pneumonia.

Pneumonia makes breathing hard because the lungs are full of liquid. It’s like when it rains too much and a tree’s branches get heavy with water…they droop and can’t hold the weight.

Parkinson’s Disease

Sometimes, when people get older—like grandmas or grandpas—they can have Parkinson’s Disease.

This disease happens because the brain gets damaged and can’t control movements very well.
It’s like the brain is a big command center for the body, just like a computer. If the command center is broken, the “keys” that make the body move don’t respond the way they should.

People with Parkinson’s Disease may have shaking in their arms and legs, and their movements can become slow.

Q

Q fever

Some animals, like sheep, goats, and cows, can carry tiny unwanted guests (bacteria). These little troublemakers live inside the animals’ bodies, making them their own homes. When humans, like me and you, touch or breathe near contaminated animals, the tiny guests can jump into human bodies and cause problems. It may feel a bit like having the flu or a cold, but that’s called Q fever.

But don’t worry! Q fever is not very common, and doctors have special medicines to chase those bad guests away.

Quadriplegia

Some people cannot move their arms and legs from the neck down. This is called Quadriplegia.

It usually happens after an accident or something that hurts the spinal cord. The spinal cord is like a highway that delivers messages between the brain and the body. When it gets damaged, the messages can’t travel down anymore.

It’s a bit like a broken lamp: when the bulb is out, the electricity can’t turn on the light. In quadriplegia, the “body’s electricity” can’t turn on the muscles.

Quick pulse

Your heart works like a pump, sending blood to every part of your body. Its beat is called a pulse—like opening and closing your hand over and over. You can feel this pulse in places like your wrist or neck.

When you run, play hard, or even feel nervous, your heart starts beating faster. That makes your pulse race, too. This faster beat is called a quick pulse.

Quarantine

Quarantine is when someone needs to stay at home, away from the outside world, for a few days because germs (like viruses or bacteria) might be inside their body. During this time, people wait to see if they get sick.

This is important because tiny villains love to spread and cause trouble. By staying home, people stop the villains from jumping to others and making a big mess.

When the time is up and doctors say it’s safe, the person can go back to the world outside!