Sudden, heavy hair loss during the growth (anagen) phase, classically caused by chemotherapy, which abruptly halts rapidly dividing follicle cells. Unlike pattern loss it is usually diffuse and reversible, with regrowth after the trigger ends — though texture or colour can change.
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Not medical advice. General education only; it does not replace diagnosis or treatment by a licensed professional. Consult a board-certified dermatologist before starting, stopping or changing any treatment.
⚠️ When to see a doctor — don’t self-treat
- Sudden patchy or circular bald spots
- Redness, scaling, pus, pain or itch (possible scarring alopecia — treat urgently)
- Broken hairs or rapid loss
- Loss with body-wide signs (weight loss, fatigue, cycle changes, acne, extra hair)
- Loss right after a new medication
- Any hair loss in a child