Why does head lice cause itching worse at night?

Head lice feed on blood from the scalp. Their bites and saliva can trigger an itchy immune response, which may continue after the lice have moved away. At night, fewer distractions and the stillness of lying in bed can make that signal more noticeable. Warmth under bedding may also increase awareness of an already irritated scalp.

Scratching can leave small marks, crusts, or broken skin. Itching alone does not confirm lice because dandruff, eczema, psoriasis, and product irritation can feel similar. Look for live crawling lice or firmly attached nits close to the scalp, especially behind the ears and near the back of the neck.

Use a bright light and a fine-toothed lice comb to inspect wet, conditioned hair, concentrating behind the ears and at the nape. If live lice are found, use an appropriate pharmacy treatment exactly as directed and repeat it when the product instructions say to do so. Wash recently used bedding, hats, and clothing, and avoid sharing combs, brushes, or headwear. Check close household contacts rather than treating everyone automatically.

Ask a pharmacist or clinician for help if you cannot tell a nit from debris, symptoms continue after correct treatment, or live lice remain. Seek prompt care for spreading redness, pus, marked swelling, or fever after repeated scratching.

Ask how to confirm live lice, which treatment fits your age and situation, when to repeat it, and how to manage scalp sores caused by scratching.