Health dictionary - M

Health dictionary


This word is used to describe a disease or condition that gets worse at time goes by, or which spreads to other parts of the body.


This is your lower jaw bone that holds your bottom teeth in place and forms your chin.


A test that shows how well nerves and muscles in the digestive system are squeezing to push along food or waste matter.


The bones in the skull that form your upper jaw are called the maxilla.


This is a serious disease that affects mainly children. It causes a rash and a high temperature and can cause inflammation of the brain. Most children are immunised against measles now, by the MMR jab, but children who have not been immunised are at risk. If a pregnant woman catches measles, it can cause a miscarriage.


The pigment that gives our skin, hair and eye colour. The amount of melanin in your skin depends on your race and whether you’re exposed to sunlight a lot.


These are the layers of tissue that cover your brain and spinal cord. If the meninges become inflamed, this is called meningitis.


This is a serious illness where the meninges become inflamed, usually because of an infection. Some types of meningitis are very serious indeed, and need treatment very quickly.


A powerful instrument that lets scientists examine things closely that cannot normally be seen with the naked eye.


A serious headache, usually with sickness as well. Some people cannot see properly when they have a migraine. A migraine can last from a couple of hours to a couple of days. They can be treated with painkillers and often by lying in a darkened room.


The smallest part of a substance.


This is a medicine that is used to relieve pain.

Mouth ulcer

This is a sore patch inside your mouth. Mouth ulcers are really painful, and are made worse if you eat or drink something acidic like lemon squash. They can be treated using gels you can buy from your chemist.

MRI scan

A magnetic resonance imaging (MRI) scan produces images of what's going on inside your body. It uses very strong magnetic fields (like a big magnet) and radio waves. An MRI scanner looks like a tunnel that you lie inside. It takes a while but you can watch a video or listen to music while you're in there, so it's not that as bad as it sounds. You do have to lie very still though, but it doesn't hurt at all.

Mucous membrane

The lining of many parts of the body, like your nose and mouth. They let out a fluid (mucus) that keeps everything moist.


This is a thick, slimy fluid released by the mucous membranes.


A seroius illness that mainly affects children. Most children are immunised against mumps now, by the MMR jab, but children who have not been immunised are at risk.


We have lots of muscles in our body – some are very small, others are very big. Muscles work by contracting (squeezing tight) and relaxing to make things move.