Fever, Sweats, and Hot Flashes (PDQ®): Supportive care - Patient Information [NCI]

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Fever, Sweats, and Hot Flashes (PDQ®): Supportive care - Patient Information [NCI]

This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http://cancer.gov or call 1-800-4-CANCER.

Fever, Sweats, and Hot Flashes


Fever, sweats, or hot flashes may be side effects of cancer or its treatment.

In patients with cancer, fever may be caused by infection, a tumor, or reactions to drugs or blood transfusions.

Sweating is the body's way of lowering body temperature by causing heat loss through the skin. In patients with cancer, sweating may be caused by fever, a tumor, or cancer treatment.

Hot flashes can also cause too much sweating. They may occur in natural menopause or in patients who have been treated for breast cancer or prostate cancer.

Fever, sweats, and hot flashes affect quality of life in many patients with cancer.

A treatment plan to help manage fever, sweats, or hot flashes is based on the patient's condition and goals of care. For some patients, relieving symptoms and improving quality of life is a more important goal than treating the fever to prolong life.

This summary describes the causes and treatment of fever, sweats, and hot flashes in cancer patients.

Causes of Fever in Patients with Cancer

Fever is a rise in body temperature caused by the body's response to illness.

Normal human body temperature changes during each 24-hour period according to a definite pattern. It is lowest in the morning before dawn and highest in the afternoon. Temperature control actions in the body keep the amount of heat that is made equal to the amount lost. This keeps body temperature normal.

An abnormal rise in body temperature is caused by either a condition called hyperthermia or fever. Hyperthermia is caused by a breakdown in the body's temperature control actions. In fever, the temperature controls in the body are working as they should, but body temperature rises as the body responds to illness.

There are three phases of fever:

  • In the first phase, body temperature rises as blood vessels in the skin narrow. This prevents heat from leaving the body through the skin. The skin becomes cool, the muscles contract and cause shivering or chills, and the body makes more heat. The body continues to make and keep heat until a new, higher temperature is reached.
  • In the second phase, a new, higher temperature has been reached. The amount of heat the body makes and loses is the same. Shivering stops, and the body stays at the new, higher temperature.
  • In the third phase, body temperature falls to normal as blood vessels in the skin open and move blood from inside the body to the skin surface. This helps get rid of extra heat. Sweating occurs and helps to cool the body.

Certain problems are more likely in older people or the very young. In older people, the temperature control centers in the brain may not work the way they should and can lead to hyperthermia. This may cause irregular heartbeat, lack of blood flow to parts of the body, confusion, or heart failure. In children between 6 months and 6 years old, high fever may lead to seizures.

There are many possible causes of fever in patients with cancer.

The main causes of fever in patients with cancer are reactions to:

  • Infection.
  • Substances made by tumor cells.
  • Medicines, including:
    • Chemotherapy drugs.
    • Biological response modifiers.
    • Antibiotics, such as vancomycin and amphotericin.
  • Blood transfusions.
  • Graft-versus host disease, which occurs when a donor's transplanted tissue attacks the patient's tissue.

Other causes of fever in cancer patients include:

  • Drug withdrawal.
  • Neuroleptic malignant syndrome (NMS).
  • Blockages of the bladder, bowel, or kidney.
  • Treatment to stop blood flow to a tumor.
  • Blood clots.
  • Connective tissue disorders.
  • Brain hemorrhage or stroke.

Patients with fever need to be checked carefully for signs of infection.

The doctor will ask questions about past medical problems, check all medicines the patient is taking, and do a physical exam to look for the cause of fever. Patients, especially those who have fever and neutropenia (a very low white blood cell count), will have a complete checkup for signs of infection. Some of the areas the doctor will check include:

  • The skin and skin folds (for example, the breasts, armpits, or groin).
  • Body openings (mouth, ears, nose, throat, urethra, vagina, and rectum).
  • Areas on the skin where needles have been put in or biopsies have been done.
  • The teeth, gums, tongue, nose, throat, and sinuses.
  • Areas where lines into veins or arteries have been placed.
  • Areas where tubes have been placed, such as stomach tubes.
  • Samples of urine, sputum, and blood.

Patients with neutropenia may not show the usual signs of infection. These patients need to be checked often and should see their doctor if they have a fever.

Treatments to Relieve Fever in Patients with Cancer

Treatment for fever depends on the cause, stage of the disease, and goals of care.

The symptoms of fever in very weak cancer patients include fatigue, muscle pain, sweating, and chills. Fever may be controlled by treating the cause of the fever. Intravenous (IV) fluids and nutrition support or other measures can also help make the patient more comfortable. The specific treatments depend on the stage of cancer and the kind of care the patient wants. For example, some patients who are near the end of life may decide not to be treated for the cause of the fever, such as pneumonia or other infections. Instead, they may want to receive general comfort care.

Fever caused by infection may be treated with antibiotics.

Antibiotics may be used to treat fever caused by bacterial infection. Antibiotic therapy may be given by IV in the hospital or at home, or may be given by mouth. Drugs to treat fungal infections or viral infections may be added if needed.

Fever caused by tumors may be treated with antitumor therapy or drug therapy.

Fever caused by tumors is called paraneoplastic fever. This fever may occur when substances released by cancer cells affect the way nearby cells and tissue work. Fever caused by tumors may come in a pattern at certain times of day, or on and off for days or weeks. This fever is usually treated with standard treatment for the specific type of cancer. If the treatment doesn't work, takes time to work, or is not available, nonsteroidal anti-inflammatory drugs (NSAIDs) may be used.

Fever related to drugs may be treated in different ways.

Sometimes fever may be caused by a reaction to drugs given to treat the cancer or prevent infection. Drugs that are known to cause fever include some types of chemotherapy, biological response modifiers, and antibiotics. There may be a period of time between when drug therapy starts and when fever begins. This can make it hard to find out what is causing the fever.

The doctor may control the fever by changing how and when the drug causing it is given. Acetaminophen, NSAIDs, and steroids may also be given before the patient receives the drug that causes the fever.

Fever related to a transfusion may be prevented.

Cancer patients may have a fever caused by a reaction to blood products (for example, receiving a blood transfusion). Acetaminophen or antihistamines are sometimes given before a transfusion, to help prevent fever.

Supportive care measures help relieve the discomfort of fever.

Along with treatment of the cause of fever, comfort measures may also help relieve the discomfort that goes along with fever, chills, and sweats.

The following may help relieve fever:

  • Give plenty of liquids.
  • Remove extra clothing and covers.
  • Bathe or sponge the patient with lukewarm water.

The following may help relieve chills and sweats related to fever:

  • Replace wet blankets with warm, dry blankets.
  • Keep the patient away from drafts.
  • Keep the patient's room warm.

NSAIDs or acetaminophen may be used to relieve fever in some patients.

Nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen may also be prescribed to relieve symptoms. Aspirin may help lower fever, but should be used with caution in patients with Hodgkin lymphoma and cancer patients who have an increased risk of thrombocytopenia (low blood platelets). Aspirin is not recommended in children with fever because of the risk of Reye syndrome.

Causes of Sweats and Hot Flashes in Patients with Cancer

In patients with cancer, sweats and hot flashes may be caused by the tumor, its treatment, or other conditions.

Sweating happens with disease conditions such as fever and may occur without disease in warm climates, during exercise, and during hot flashes in menopause. Sweating helps balance body temperature by allowing heat to evaporate through the skin.

Sweats and hot flashes are common in patients with cancer and in cancer survivors. Sweating is more common in certain types of cancer, such as Hodgkin lymphoma, pheochromocytoma, and some neuroendocrine tumors.

Many patients treated for breast cancer and prostate cancer have hot flashes.

Menopause in women can have natural, surgical, or chemical causes. Chemical menopause in women with cancer is caused by certain types of chemotherapy, radiation, or hormone therapy with androgen (a male hormone).

"Male menopause" in men with cancer can be caused by orchiectomy (surgery to remove one or both testicles) or hormone therapy with gonadotropin-releasing hormone or estrogen.

Treatment for breast cancer and prostate cancer can cause menopause or menopause-like effects, including severe hot flashes.

Certain types of drug therapy can cause sweats.

Drugs that may cause sweats include the following:

  • Tamoxifen.
  • Aromatase inhibitors.
  • Opioids.
  • Tricyclic antidepressants.
  • Steroids.

Treatment of Sweats and Hot Flashes in Patients with Cancer

Sweats are controlled by treating their cause.

Sweats caused by fever are controlled by treating the cause of the fever. (See the Treatments to Relieve Fever in Patients with Cancer section for more information.) Sweats caused by a tumor are usually controlled by treatment of the tumor.

Hot flashes may be controlled with estrogen replacement therapy.

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

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.

Other drug therapy may be useful in some patients.

Studies of non-estrogen drugs to treat hot flashes in women with a history of breast cancer have reported that many of them do not work as well as estrogen replacement or have side effects. Megestrol (a drug like progesterone), certain antidepressants, anticonvulsants, and clonidine (a drug used to treat high blood pressure) are non-estrogen drugs used to control hot flashes. Some antidepressants may change how other drugs, such as tamoxifen, work in the body. Side effects of drug therapy may include the following:

  • Antidepressants used to treat hot flashes over a short period of time may cause nausea, drowsiness, dry mouth, and changes in appetite.
  • Anticonvulsants used to treat hot flashes may cause drowsiness, dizziness, and trouble concentrating.
  • Clonidine may cause dry mouth, drowsiness, constipation, and insomnia.

Patients may respond in different ways to drug therapy. It is important that the patient's health care providers know about all medicines, dietary supplements, and herbs 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.

If one medicine does not improve symptoms, switching to another medicine may help.

Comfort measures may help relieve sweats related to cancer.

Comfort measures may be used to treat sweats related to cancer. Since body temperature goes up before a hot flash, doing the following may control body temperature and help control symptoms:

  • Wear loose-fitting clothes made of cotton.
  • Use fans and open windows to keep air moving.
  • Practice relaxation training and slow, deep breathing.
  • Learn and practice self-hypnosis.

Herbs and dietary supplements should be used with caution.

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. Studies of ground flaxseed to treat hot flashes have shown mixed results.

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

Acupuncture may be used to treat hot flashes.

Several studies have looked at the use of acupuncture to treat hot flashes. Results are not clear and more studies are needed. (See the Vasomotor symptoms section in the PDQ summary on Acupuncture for more information.)

Current Clinical Trials

Check NCI's list of cancer clinical trials for U.S. supportive and palliative care trials about fever, sweats, and hot flashes, neutropenia, hot flashes and hot flashes attenuation that are now accepting participants. The list of trials can be further narrowed by location, drug, intervention, and other criteria.

General information about clinical trials is also available from the NCI Web site.

Changes to This Summary (01 / 29 / 2013)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Editorial changes were made to this summary.

Questions or Comments About This Summary

If you have questions or comments about this summary, please send them to Cancer.gov through the Web site's Contact Form. We can respond only to email messages written in English.

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About PDQ

PDQ is a comprehensive cancer database available on NCI's Web site.

PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.

PDQ contains cancer information summaries.

The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.

Images in the PDQ summaries are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in the PDQ summaries, along with many other cancer-related images, are available in Visuals Online, a collection of over 2,000 scientific images.

The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.

Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.

PDQ also contains information on clinical trials.

A clinical trial is a study to answer a scientific question, such as whether one method of treating symptoms is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. Some patients have symptoms caused by cancer treatment or by the cancer itself. During supportive care clinical trials, information is collected about how well new ways to treat symptoms of cancer work. The trials also study side effects of treatment and problems that come up during or after treatment. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients who have symptoms related to cancer treatment may want to think about taking part in a clinical trial.

Listings of clinical trials are included in PDQ and are available online at NCI's Web site. Descriptions of the trials are available in health professional and patient versions. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).

Last Revised: 2013-01-29

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