How can you tell if you have lice in your head? - briefly
Inspect the scalp and hair for live insects about the size of a sesame seed, their white nits attached close to the roots, and persistent itching. Use a fine-tooth comb on wet hair to confirm the presence of lice or nits.
How can you tell if you have lice in your head? - in detail
Detecting an infestation of head lice requires careful visual examination and awareness of characteristic symptoms.
First, observe the scalp and hair for live insects. Adult lice are about the size of a sesame seed, grayish‑brown, and move quickly. Nymphs are smaller, pale, and less mobile. Use a fine‑toothed comb on damp, conditioned hair, pulling the comb from the scalp to the ends. After each pass, wipe the teeth on a white tissue or rinse the comb in water; any attached insects or brownish‑black specks indicate presence.
Second, look for nits—oval, white or yellowish eggs firmly attached to the hair shaft within a quarter‑inch of the scalp. Nits are cemented and do not slide easily when the hair is brushed. A high concentration of nits, especially in the nape, behind the ears, and at the hairline, is a strong indicator.
Third, note clinical signs experienced by the host. Persistent itching, especially after bathing or during warm weather, suggests an allergic reaction to lice saliva. Secondary redness, small sores, or crusted lesions may appear from scratching. Distinguish these from dandruff; dandruff flakes fall off easily and are not attached to hair strands.
Fourth, perform a systematic check. Divide the head into sections (top, sides, back) and examine each for at least five minutes, using a magnifying lens if needed. Record any findings to track the infestation’s extent.
Fifth, confirm the diagnosis. If live lice or viable nits are found, treatment should begin immediately. In ambiguous cases, seek professional evaluation from a healthcare provider or licensed lice‑removal service.
Finally, prevent re‑infestation by washing bedding, hats, and personal items in hot water (≥130 °F) or sealing them in plastic bags for two weeks. Regular combing with a fine‑toothed nit comb for a week after treatment helps ensure complete eradication.