Side effects
Hair loss
Some cancer treatments cause hair loss, called alopecia. Not every treatment does, and in most cases hair grows back after treatment ends.
Why it happens
Chemotherapy can damage the cells that make hair grow, because they divide quickly. Radiation can cause hair loss only in the area being treated. Hair loss can affect the head, eyebrows, eyelashes and body hair.
What to expect
When treatment causes hair loss, it often starts a few weeks after the first treatment. Hair may thin or fall out completely, sometimes in clumps. Your scalp may feel tender. Hair usually starts to grow back a few weeks to months after treatment ends, and it may be a slightly different color or texture at first.
What helps
- Ask about scalp cooling. Cooling caps worn during some chemotherapy infusions may reduce hair loss.
- Be gentle with your hair: use a mild shampoo and soft brush, and avoid heat, dyes and perms.
- Consider cutting your hair short before treatment, which can make hair loss feel less sudden.
- Protect your scalp from sun and cold with sunscreen, a hat or a scarf.
- Plan ahead for a wig if you want one. Some insurance plans cover a “cranial prosthesis” with a prescription.
When to call your care team
Hair loss itself isn’t dangerous, but tell your care team if your scalp becomes red, painful or broken, or if hair loss is affecting how you feel. Support is available.
Questions to ask your care team
Bring these to your next visit, or write down your own.
- Is my treatment likely to cause hair loss?
- When might it start, and how much might I lose?
- Is scalp cooling an option for me?
- Does insurance cover a wig or scalp prosthesis?
Go deeper
More detailed information
For more clinical detail, our affiliate, Northside Hospital Cancer Institute, covers this topic in depth.
Hair loss and cancer treatment (National Cancer Institute)Sources
This page is for general education and does not replace advice from your doctor or care team. Last updated October 26, 2026.