What Causes Alopecia Areata?

The exact reason this immune response begins in one person at a particular time is often unclear. It is not caused by dirty hair, ordinary shampooing, wearing hats, or sharing personal items, and the condition is not contagious.

Inflammatory signals gather around the base of an active hair follicle and interrupt its growth cycle. The hair then sheds, often leaving a smooth round or oval patch. The follicle itself generally remains present, which is why regrowth can occur, although the timing and pattern are unpredictable.

Inherited susceptibility may contribute, but having a relative with alopecia areata does not determine that someone will develop it. Alopecia areata can occur alongside other immune-related conditions, yet that association does not mean every affected person has another illness. Tests are chosen according to symptoms, family history, and examination findings.

Record when each patch appeared, photograph it in consistent lighting, and mention eyebrow, eyelash, nail, or body-hair changes at an appointment. Bring a list of medicines and supplements and describe itching, scaling, pain, illness, or major life changes. These details help a clinician separate alopecia areata from infection, traction, breakage, and other causes of hair loss.

Gentle scalp care and sun protection can reduce irritation but do not switch off the underlying immune tendency. Avoid blaming a particular food or stressful event without a clear pattern, and do not begin a restrictive diet unless a qualified clinician has identified a nutritional reason.

Arrange a medical review for new, unexplained bald patches or rapid shedding. Seek earlier attention when hair loss is accompanied by scalp pain, marked redness, scale, crusting, drainage, broken skin, or fever, since these features can signal a condition other than uncomplicated alopecia areata. Loss of eyelashes or extensive scalp coverage also merits timely assessment.

Ask which examination findings support alopecia areata, whether your symptoms suggest testing for another condition, and how the extent of hair loss affects treatment choices. It is also useful to discuss which changes to monitor and when photographs or a follow-up examination should be repeated.