Head lice are small insects that live in human hair and feed from the scalp. They are common, particularly among children, and spread mainly through direct hair-to-hair contact. They are not caused by poor hygiene and do not carry disease.
How to recognize head lice
The only reliable way to confirm head lice is to find a live, moving louse. They are grey-brown and range from pinhead size to about the size of a sesame seed. Eggs are attached firmly to individual hairs near the scalp. Empty egg cases, called nits, may remain after treatment.
Possible signs include scalp itching, a tickling feeling, scratch marks or small sores. Some people have no symptoms, especially during a first infestation.
How they spread
Head lice crawl; they do not jump, fly or live on pets. Spread usually requires close head-to-head contact. Sharing brushes, hats or bedding is a less common route because lice survive poorly away from the scalp.
Check household members and other close contacts with a fine-toothed detection comb. Treat everyone with confirmed live lice at the same time. Someone who has only old nits may not have an active infestation.
Wet combing
Wet combing can remove lice without an insecticide:
- Wash the hair with ordinary shampoo and apply plenty of conditioner.
- Untangle the hair with a wide-toothed comb.
- Use a fine-toothed detection comb from the roots to the ends, section by section.
- Check and wipe the comb after each stroke.
- Repeat the process on days 1, 5, 9 and 13, then check again on day 17.
Thick, long or tightly curled hair may take longer and is easier to manage in small sections.
Medicated treatments
A pharmacist can recommend a suitable lotion or spray if wet combing is unsuccessful or impractical. Follow the instructions exactly because the application time and need for a second treatment vary between products. Using too little, rinsing too early or missing a repeat dose can cause treatment failure.
Ask for professional advice before treating a young child, during pregnancy or breastfeeding, or if the scalp is inflamed or broken. Do not combine treatments or repeatedly use the same product when live lice remain. Resistance can occur, and a pharmacist or clinician may recommend a different option.
What is not needed
- Children do not usually need to stay away from school once appropriate treatment has started.
- There is no need for intensive house cleaning or insecticide sprays.
- Do not use medicated products to prevent lice when no live lice are present.
- Essential oils, electric combs and household chemicals are not proven safe and effective substitutes for recommended treatment.
Wash combs and brushes and avoid sharing them during treatment. Routine cleaning of pillowcases and items in recent direct contact with the hair is reasonable, but lice depend on the human scalp and do not infest the home.
When to seek advice
Speak to a pharmacist or healthcare professional if you are unsure whether live lice are present, recommended treatment has been used correctly but lice remain, or scratching has caused spreading redness, pain, pus or fever.
Sources
Reviewed: 28 August 2026
Medical disclaimer: This information is general and does not replace advice from a pharmacist or qualified healthcare professional.