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Fever, Sweats, and Hot Flashes (Patient) (cont.)

Sweats and Hot Flashes


Sweat is made by sweat glands in the skin. Sweating helps to keep the body cool and can occur with disease or fever, when in a warm environment, exercising, or as part of hot flashes experienced with menopause. Most breast cancer and prostate cancer patients report having moderate-to-severe hot flashes. Distressing hot flashes seem to be less frequent and gradually decrease with time in most postmenopausal women who do not have breast cancer. Hot flashes occur in most men with prostate cancer who have had surgery to remove the testicles or who receive drugs to stop the testicles from making testosterone.


Sweats in the cancer patient may be associated with the tumor, cancer treatment, or other medical conditions that are not related to the cancer. Sweats are a typical symptom of certain types of tumors such as Hodgkin lymphoma, pheochromocytoma, or tumors involving the nervous system and endocrine system. Sweats may also be caused by:

  • Fever.
  • Female menopause (natural menopause, surgical removal of the ovaries, or damage to ovaries from chemotherapy, radiation, or hormone therapy).
  • Male menopause (surgical removal of the testicles or hormone therapy).
  • Drugs such as tamoxifen, aromatase inhibitors, opioids, antidepressants, and steroids.
  • Problems in the hypothalamus in the brain.
  • Sweating disorders.



Treatment of sweats caused by fever is directed at the underlying cause of the fever. (Refer to the fever Treatment section for more information.) Sweats caused by a tumor are usually controlled by treatment of the tumor.

Hot flashes

Hot flashes associated with natural or treatment-related menopause can be effectively controlled with estrogen replacement therapy. Many women are not able to take estrogen replacement (for example, women with breast cancer). Hormone replacement therapy that combines estrogen with progestin may increase the risk of breast cancer or breast cancer recurrence.

Studies of non-estrogen drugs to treat hot flashes in women with a history of breast cancer have reported that many of them are not as effective as estrogen replacement or have unwanted side effects. The most effective of these include megestrol (a drug similar to progesterone), certain antidepressants, anticonvulsants, and clonidine (a drug used to treat high blood pressure). Some antidepressants may change how other drugs, such as tamoxifen, work in the body. Different patients may respond in different ways to certain drugs and some side effects can be serious. It is important that the members of a patient's health care team know about all medicines and herbals the patient is taking.

Drugs that may relieve nighttime hot flashes or night sweats and improve sleep at the same time are being studied in clinical trials.

Studies of vitamin E for the relief of hot flashes show that it is only slightly better than a placebo (pill that has no effect). Most studies of soy and black cohosh show they are no better than a placebo in reducing hot flashes. Soy contains estrogen-like substances; the effect of soy on the risk of breast cancer growth or recurrence is not clear. Ground flaxseed continues to be studied for its potential to relieve hot flashes.

Claims are made about several other plant-based and natural products as remedies for hot flashes. Since little is known about how they work or whether they affect the risk of breast cancer, women should be cautious about using these products, including dong quai, milk thistle, red clover, licorice root extract, and chaste tree berry.

Treatment of hot flashes in men who have been treated for prostate cancer may include estrogens, progesterone, antidepressants, and anticonvulsants. Certain hormones (such as estrogen) can make some cancers grow. The effect of hormone use on the growth of prostate cancer is being studied.

Side effects of antidepressants used to treat hot flashes over a short period of time are minor, including nausea, drowsiness, dry mouth, and changes in appetite. Side effects of anticonvulsants used to treat hot flashes include drowsiness, dizziness, and trouble concentrating. Side effects of clonidine include dry mouth, drowsiness, constipation, and insomnia.

If one medication does not improve symptoms, switching to another medication may be helpful.

General Treatments to Relieve Symptoms

Comfort measures are used for general treatment of cancer-related sweats. Since body temperature goes up before a hot flash, the following ways may control body temperature and help manage symptoms:

  • Wear loose-fitting clothes.
  • Use fans and open windows to keep air moving.
  • Learn relaxation training and slow, deep breathing.
  • Use self-hypnosis.
eMedicineHealth Public Information from the National Cancer Institute

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