Health dictionary - D

Health dictionary


This is when the surface of your head starts flaking, which leave you with white bits in your hair. It’s not catching but it doesn’t look nice. You can get rid of dandruff with a shampoo.

Day surgery

If you come in for a test or an operation and go home the same day, you’ve had day surgery. More and more tests and operations are done like this as you’re more likely to get better quickly when you’re at home with your family.


This is when a person cannot hear – either completely or partly. Hearing aids can help some people with deafness, or cochlear implants are used for some people. Deaf people often communicate using a sign language called BSL (British Sign Language).


When the body stops working completely – the person has died. This means that the heart has stopped, the person is not breathing anymore and the brain has switched off.


If you don't have enough water in your body, you can feel very unwell. When you sweat, you lose water and it's easy to get dehydrated when it's hot, so you need to drink plenty of water. You can also lose a lot of water when you’re sick with diarrhoea and vomiting.


A person who is trained to look after your teeth and gums and fix any problems if they occur. There are also dentists who specialise in fitting braces to straighten teeth.


The study of the skin and skin diseases.


This is the condition where the amount of glucose in the blood is too high.


This is the label that a doctor gives your symptoms, so that they can work out how to treat you.


This is a way of removing waste products from the blood when your kidneys aren’t working properly. There are two types: haemodialysis and peritoneal dialysis.


This is a sheet of muscle which separates your chest from your abdomen. It helps you breathe and also stops your intestines moving up and blocking your chest. When you have hiccups, it's really your diaphragm squeezing tight!


When you’ve got diarrhoea, you’ll have very runny poo and will need to go to the toilet a lot. Remember to drink lots of fluids – this will stop you feeling worse.


The study of how what we eat can affect our health. Dietitians are the people who check what we eat and suggest ways of improving our diet so we can feel healthier. They also make up special diets for people with diseases that affect their eating.

Digestive system

This consists of your oesophagus, stomach, duodenum, small bowel, large bowel, and rectum. Its job is to break down the food you eat so the goodness can be absorbed and get rid of the waste stuff as poo.


A diuretic is a medicine that reduces the amount of water in the body by making you wee.


A person who gives something like blood or organs to another person.


The amount of medicine you are supposed to take at a certain time. You should always follow the dose instructions your doctor or pharmacist gives you – taking too much or too little medicine can be dangerous.


This is the first part of your small bowel.


People who have trouble reading because the words jump about on the page have something called dyslexia. They may also write certain letters backwards or spell words wrong all the time. Teachers are getting much better at spotting children with dyslexia now, so they can make learning easier for you.


The medical word for when you have trouble swallowing.