Decorative image

Causes of sweating

Sweating can be a symptom of cancer, or may be due to cancer treatment. It can be very distressing. It can also be embarrassing if you are in a social situation.

There are things you can do to help. And your doctor may be able to prescribe medicines to control it.

Why do we sweat?

Sweating is how our bodies keep cool. We have sweat glands in the skin over most parts of our body. They are in the layer of the skin called the dermis. The nerve cells in the dermis control sweating.

Although we don’t realise it, we are actually constantly sweating. The amount of sweat we make depends on:

  • what we are doing
  • our emotional state
  • the temperature around our body

We sweat more when: 

  • it is hot
  • we exercise
  • we are nervous, angry or upset
  • we go through the menopause (women only)
  • we are ill
  • we take medicines that cause sweating

Causes of sweating

When you have cancer, things that may cause sweating include the following:


Infection is one of the most common causes of sweating in people who have cancer. Infection can give you a high temperature and your body sweats to try and reduce it. Treating the infection can control or stop the sweating.

The cancer itself

Some cancers can cause you to sweat more than usual. These include:

  • non-Hodgkin lymphoma
  • Hodgkin lymphoma
  • carcinoid tumours
  • leukaemia
  • mesothelioma
  • bone cancer
  • liver cancer

People with advanced cancer of any type may also have sweating. 

Hormone changes

Changes in hormone levels can cause hot flushes and sweats. Your hormone levels may change because of the cancer itself, or because of treatment such as surgery, chemotherapy, radiotherapy or hormone therapy.

Treatment for breast cancer can put women into an early menopause. For some women, this causes hot flushes and sweats. Women who have already had their menopause can have hot flushes again when they start hormone treatment.

Men can have hot flushes and sweating when they have hormone treatment for prostate cancer or breast cancer, because it reduces the amount of testosterone in the body.

Recent research is helping us to understand why changes in sex hormone levels cause hot flushes and sweats. This is needed in order to find better treatment for these symptoms.

Medicines and cancer drugs

Sweating and hot flushes can be a side effect of some drug treatments, including chemotherapy and morphine.

Last reviewed: 
20 Feb 2019
  • Cancer and its management (6th edition)
    J Tobias and D Hochhauser
    Wiley-Blackwell, 2010

  • European guideline on chronic pruritus.
    Weisshaar E, Szepietowski JC, Darsow U and others. (2012)
    Acta Dermato Venerologica. 92 (5): 565-81