What causes hair loss in people with cancer?

Hair loss is not a symptom of cancer and cancer does not cause you to lose your hair. But cancer treatments can affect your hair in the following ways:

  • Some treatments may make your hair fall out. You may lose just some of your hair or it may all fall out. This is usually temporary.
  • Other treatments can cause permanent hair loss in parts of your body.
  • You may not lose your hair, but the condition and texture of your hair may change. This is usually temporary.

If you do lose your hair, you could wear a wig, scarf or bandana to cover up hair loss from your head.

Hair loss from chemotherapy

Chemotherapy uses anti-cancer drugs to destroy cancer cells. These are called cytotoxic drugs. Chemotherapy drugs disrupt the way cancer cells grow and divide. They also affect some normal cells. This includes the cells of the hair follicles.

Hair loss caused by chemotherapy is called chemotherapy-induced alopecia (CIA).

Healthy cells can usually recover from damage caused by chemotherapy. This means that after chemotherapy treatment ends, your hair will usually grow back.

Many people worry that they will lose their hair if they have chemotherapy. A lot of chemotherapy drugs cause hair loss, but not all of them. Your specialist nurse or chemotherapy nurse can tell you if your treatment is likely to cause hair loss.

If you are having chemotherapy and you do not lose your hair, this does not mean that the chemotherapy is not working.

The level of hair loss can vary. It may be hardly noticeable, or you may lose all your hair. This depends on the:

  • drug or combination of drugs you are having
  • dose of each drug
  • way your body reacts – different people react in different ways to the same drug.

Before you start chemotherapy, your cancer doctor or chemotherapy nurse will talk to you about side effects and how likely you are to lose your hair. You will not start treatment until you have given your consent.

A process called scalp cooling can reduce or prevent hair loss due to chemotherapy. It is not suitable for everyone having chemotherapy.

As well as the hair on your head, you may lose other body hair, such as:

  • eyebrows and eyelashes
  • nasal hair
  • facial hair (beard or moustache)
  • chest hair
  • leg, arm and underarm hair
  • pubic hair.

These changes are almost always temporary. We have some practical tips to help you cope with hair loss.

When will my hair fall out?

If your treatment causes hair loss, it will usually start about 2 to 3 weeks after your first chemotherapy session. Sometimes it can start within a few days, but this is rare.

You may notice hair on your pillow in the morning. You may also see more hair coming out when you brush, comb or wash it.

Hair loss affects people in different ways. Some people only lose some of their hair. Others lose all their hair over several weeks. Occasionally, people lose all their hair over 1 or 2 days. This can be very upsetting. Sometimes your hair may start to grow back between treatments.

Even if you do not lose all your hair, it may become dry and break more easily. All types of hair can be affected. But Afro hair (hair type 4 coily) is naturally more fragile and more vulnerable to damage from chemotherapy. Looking after your hair may help it stay in good condition. When your hair falls out, your scalp may feel tender or sore.

We have more information about looking after your hair and scalp.

Will my hair grow back after chemotherapy ?

Hair loss from chemotherapy is almost always temporary. Your hair should start to grow back after treatment ends, but it may be different from the hair you had before. It may grow back:

  • curlier, straighter, finer or fluffier
  • a different colour
  • unevenly, or at different speeds in different areas.

Facial hair, such as beards and moustaches, may also grow back patchy or a different colour. It may take a while for facial hair to get back to what it was like before treatment.

About 3 to 6 months after treatment ends, your head will probably have a covering of very short hair. By 12 months after your treatment ends, you should have an idea of how thick your hair will be. Afro hair grows more slowly so it may take longer to know what your hair will be like.

Very rarely, hair loss can be permanent. Some chemotherapy drugs can permanently damage the hair follicles. Other chemotherapy drugs can have the same effect in high doses.

Your hair may only partly grow back. It may also be thinner than before. Your doctors or nurses can talk to you about this before you start treatment. Unfortunately, there is no way to tell if hair loss will be permanent. Scalp cooling may help reduce the risk of permanent hair loss in some situations.

Hair loss from radiotherapy

Radiotherapy uses high-energy rays called radiation to treat cancer. It destroys cancer cells in the area where the radiotherapy is given.

Some normal cells in the area being treated can also be damaged by radiotherapy. This can cause side effects, including hair loss.

For external beam radiotherapy, a radiotherapy machine aims high-energy rays at the area of the body being treated. You may lose hair where the radiation beam:

  • enters the body
  • leaves the body.

You can ask your cancer doctor or radiographer to show you where your hair may fall out.

The amount of hair loss depends on the dose of radiotherapy, and the number of treatments. It also depends on where you have radiotherapy. For example:

  • If you have radiotherapy to your head, you will probably lose some hair from your scalp. This will be in the areas where the radiotherapy beam enters and leaves your head.
  • If you have radiotherapy for breast cancer, and the treatment area includes your armpit, you are likely to lose your underarm hair.
  • If you have radiotherapy to your head or neck, you may lose your beard.

Hair usually begins to fall out after 2 to 3 weeks. It takes about a week for the hair in the treatment area to fall out completely.

Will my hair grow back after radiotherapy?

Hair regrowth after radiotherapy depends on different things, including the:

  • type and dose of treatment
  • number of treatments
  • area of your body affected.

Your radiographer can usually tell you if your hair is likely to grow back.

Your hair can start to grow back once the skin has healed. This is usually 3 to 9 months after treatment ends. If you have had treatment with a high dose of radiotherapy, it may take longer. The hair that grows back may be:

  • thinner
  • patchy
  • a different colour.

Sometimes the hair loss is permanent. This can be more upsetting if it affects the hair on your head. You may find it helpful to talk to your specialist nurse or radiographer. Or you can talk to one of our cancer support specialists for free on 0808 808 00 00.


If you are having an operation on a part of the body that has hair, that area will be shaved. Your hair will grow back after the operation. However, it may not grow back along the scar line.

Other treatments

Some people having hormonal therapy, targeted therapy or immunotherapy notice that their hair becomes thinner. This is usually mild, and the hair grows back after treatment ends. If you have a beard, you may have less beard growth.

Your hair may:

  • change colour
  • be finer
  • be curlier
  • be more brittle.

Different therapies have different side effects. Your cancer doctor or specialist nurse can tell you more about the treatment you are having and its possible effects on your hair.

Questions to ask your healthcare team

Different treatments affect hair in different ways. Your doctor, nurse or radiographer can tell you more about what to expect. Here are some questions you may like to ask them:

  • How will the treatment affect my hair?
  • How soon after starting treatment will my hair start falling out? How quickly will it fall out?
  • Will I lose hair from other parts of my body?
  • Which parts of my body might be affected by hair loss from radiotherapy?
  • Is there anything I can do to prevent hair loss?
  • Is scalp cooling an option for me to help prevent hair loss from chemotherapy?
  • Will my hair grow back after treatment ends?
  • How long after treatment will my hair start to grow back?
  • Can I get financial help to buy a wig or hairpiece?
  • Where can I get suitable scarves, hats and other head coverings?

About our information

  • References

    Below is a sample of the sources used in our cancer pain information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

    Cancer Hair Care website: www.cancerhaircare.co.uk (accessed June 2022).

    Dilawari A, Gallagher C, Alintah P, et al. Does scalp cooling have the same efficacy in Black patients receiving chemotherapy for breast cancer? Oncologist, 2021; Volume 26(4):292-e548. Available from www.doi:10.1002/onco.13690 (accessed June 2022).

    Kinoshita T, Nakayama T, Fukuma E, et al. Efficacy of scalp cooling in preventing and recovering from chemotherapy-induced alopecia in breast cancer patients: The HOPE Study. Front Oncol, 2019; 9:733. Available from www.doi:10.3389/fonc.2019.00733 (accessed Oct 2022).

    Sung-chan Gwark, Sei Hyun Ahn, Woo Chul Noh, et al. Similar negative emotional impact on hair loss in neoadjuvant endocrine therapy compared to neoadjuvant chemotherapy in young women with breast cancer from patient reported outcomes. Journal of Clinical Oncology, 2020; 38:15 suppl, e19242-e19242. Available from ascopubs.org/doi/abs/10.1200/JCO.2020.38.15_suppl.e19242 (accessed June 2022).

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Chief Medical Editor, Professor Tim Iveson, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
  • structure the information clearly
  • make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 December 2022
Next review: 01 December 2026
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.