List of medical terms

When you get an itch, you usually have an urge to scratch it. Itches are best scratched with something fairly sharp, like your fingernails or a twig. If you scratch yourself too hard it can break your skin and make you bleed.

When you are sick, you don't feel very good. You can get sick by catching a disease like the flu, or from eating food that has gone bad, or even from having an allergic reaction to something like a dog or cat.

A sneeze is a sudden explosion of air from your nose and mouth. You usually sneeze if something tickles the inside of your nose, or if you have a cold. It is a good idea to cover your nose and mouth when you sneeze, like the man in the picture. A lot of mucous can come out when you sneeze and can travel a long way. If you are sick, you can make other people sick by sneezing near them.

A plant or animal is sterile if it cannot produce offspring. Something that has no living things on it or that cannot sustain living things is also called sterile. Medical equipment is usually provided in sealed packets that keep it sterile. Another word for sterile is barren. The opposite of sterile is fertile.

Sunburn is a type of burn that you get when you spend too much time in the sun without wearing sunscreen. Bad sunburn can be extremely painful, and can make your skin blister and peel. You treat sunburn the same way as any other minor burn, with special burn creams and even anaesthetic sprays. Too much exposure to the sun makes your skin age early and become dry and wrinkly, and can give you skin cancer.