Head lice are…
…a commonly occurring infection of the scalp and hair caused by tiny, wingless insects that feed by biting and sucking blood from the scalp. Head lice are not a serious health problem, but they can be a cause of worry for parents of school-aged children.
Most people who get head lice will have no symptoms. About one-third of cases will experience itching on the scalp after four to six weeks, if they develop a sensitivity to louse saliva. Some people will also experience swelling in the glands around the side of the head, ears and neck.
Read more about head lice in the factsheet for the general public.