Head lice are tiny parasitic insects that infest the hair on your head. They survive by feeding on blood and they feed once or more per day. Up to 12 million people get headlice each year in the United States alone. A similar problem, body lice, is less common in developed countries.

The most common symptom identifying head lice is scalp itching. The itchiness is caused by the saliva and feces of the lice, which irritate the skin. Despite being the primary symptom of a headlouse infestation, an itchy scalp is not grounds for a diagnosis of headlice. To make a proper diagnosis, it is necessary to make a thorough examination of the head, and headlice should only be diagnosed if you find an actual live, crawling headlouse specimen. It is imperative to properly diagnose headlice, because only people with an actual headlouse problem should be treated with the chemical shampoos or soaps that are used to kill lice.

Finding headlice on someone who has it isn't difficult; lice are most frequently found at the nape of the neck and base of the ears, and the insects can be seen by the naked eye. Lice are unable to fly or jump, so it is unlikely they will stray from their given host unless there is a lot of head-to-head contact. However, if lice are discovered it is a good idea to inspect the rest of the household members hair to prevent possible headlouse re-infestations. Lice generally do no survive on pets, but you may find the odd insect on your pet, so be sure to check them as well.

Headlice are more of a nuisance than a significant health issue. Headlice are not known to transmit diseases and after treatment, lice usually disappear after two weeks. There are many shampoos and louse treatments available on the market. Your doctor or pharmacist will be able to advise which option is the best for your family. There are fine tooth combs available for removing lice and the nits (eggs) in the hair; this works alone or coupled with a shampoo.