General medical conditions

Use the search box to learn about general medical conditions that affect children and young people.

Click here for information about specialist medical conditions, which are treated at Great Ormond Street Hospital.

Birthmarks

A birthmark is a mark on the skin that is either present at birth or develops in the first few weeks of life. Birthmarks are very common and most types do not require any treatment at all. This information sheet from Great Ormond Street Hospital (GOSH) describes the different types of birthmark that can occur, how they can be treated (if needed) and where to get help. 

Headache

Headaches affect people of all ages – many adults remember having headaches as children. Headache in children can occur on its own (primary disorder) or as a result of another condition.

Pneumonia

Pneumonia can affect one or both lungs. It is nearly always due to an infection, caused by either bacteria or viruses, and can make a child very unwell.

Conjunctivitis

Conjunctivitis is a very common eye infection. It involves the inflammation (swelling) of the conjunctiva which is the thin delicate membrane that covers the whites of the eyes and lines the inside of the eyelids.

Tooth decay

Tooth plaque is a sticky layer of bacteria (germs) which coats the teeth. When the bacteria in plaque react with sugar (from our food and drink), it produces acid. The acid causes decay or ‘cavities’ in the teeth.

Perforated ear drum

The ear drum is a thin piece of tissue that separates the middle and inner ear from the ear canal. The outer ear (the part you see) collects soundwaves which travel down the ear canal. These soundwaves make the eardrum vibrate. This vibration is transmitted first through the tiny bones (ossicles) in the middle ear, then into the inner ear, where it stimulates nerve endings and sends messages to the brain.

Tonsillitis

The tonsils are areas of tissue on both sides of the throat, at the back of the mouth. Children's tonsils help them to build up immunity and fight infection. In many children, the tonsils become repeatedly infected with bacteria and viruses, which make them swell and become painful. This is called tonsillitis.

Recurrent boils

A boil is an area of skin filled with pus, which makes it sore and swollen. If a child develops a number of boils that come and go over a period of time, they are said to have recurrent boils.