Updated 2026-09-29 · Educational only, not a diagnosis
Medical facts, drug details and treatment options on this page have not been independently medically reviewed.
What it is
Rapid hair loss during the growing phase, most commonly from chemotherapy or radiation, starting within days to weeks.
Who gets it
People receiving certain cancer treatments or exposed to some toxins.
Signs to look for
- Rapid, extensive loss within 1–4 weeks of treatment
- Can affect brows, lashes and body hair
Common causes and triggers
- Chemotherapy
- Radiation to the head
- Some toxins
How it is diagnosed
- Treatment history
Treatment and care options
These are the options commonly discussed. What suits you depends on your diagnosis — a dermatologist can help you choose.
- Scalp cooling during chemo (ask your oncology team)
- Wigs, scarves, hair systems
- Gentle care during regrowth
Outlook
Hair usually regrows after treatment ends, sometimes with a different texture.
When to see a doctor
Your oncology team can advise on scalp cooling and regrowth.
Not sure what's behind your thinning?
This content is for educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease. Speak with a qualified healthcare professional about your individual situation.