Night Sweats: Are They a Symptom of Cancer?

Medically Reviewed By: Ann S. LaCasce, MD, MMSc

Key Takeaways:

  • Night sweats involve excessive perspiration while asleep at night and often coincide with an increased heart rate and chills.
  • Night sweats can result from a variety of conditions, including some cancers; they can also be a side effect of certain treatments.
  • There are steps you can take that may help better control body temperature and ease the symptoms of night sweats.

What are night sweats?

Night sweats are episodes of excessive perspiration that occur at night while one is asleep. People who experience this condition typically report waking with damp bedclothes or sheets, having an increased heart rate, and chills. There are many causes of night sweats, most of which are not related to cancer or cancer treatment.

What causes night sweats?

Conditions that can cause night sweats include:

  • Autoimmune disorders
  • Bacterial infections
  • Certain cancers
  • Drug addiction
  • Hormonal changes associated with menopause
  • Some medications
  • Overactive thyroid or thyroid disease
  • Sleep disorders such as obstructive sleep apnea
  • Stroke
  • Tuberculosis

Why do night sweats happen?

Sweating is the body’s normal method for regulating the body’s temperature. When night sweats occur, the body’s thermostat gets confusing messages.

Which cancers can cause night sweats?

While night sweats can result from a wide range of conditions, night sweats associated with cancer tend to be drenching and often are accompanied by other symptoms such as fever and unexplained weight loss.

Unlike night sweats caused by hormonal changes in menopausal or perimenopausal women, which occur sporadically, those linked to cancer tend to be persistent. Drenching night sweats that require changing clothes are more concerning than mild night sweats.

Leukemia and lymphoma are among the cancers associated with night sweats. Those associated with leukemia usually occur in conjunction with symptoms such as fatigue, weight loss, or excessive bruising. Leukemia-related sweats may also result from daytime fevers. Excessive sweating is also linked to carcinoid tumors and adrenal tumors.

Night sweats can be a side effect of some cancer treatments, particularly certain types of hormone therapy commonly used to treat breastgynecologic, and prostate cancers. Other medications, such as opioids, steroids, and antidepressants, can also cause night sweats.

How can I avoid night sweats?

Fortunately, there are steps you can take that may help better control body temperature and ease the symptoms of night sweats:

  • Use sheets and bedclothes made from natural fibers, like cotton. You might also want to try wick-away fabrics that absorb moisture from the skin and dry quickly.
  • Sleep with one foot or leg out from under the covers. This can help cool your body temperature.
  • Use air conditioning or fans to keep air moving and the room temperature cool.
  • Take a cool shower before bed.
  • Try to maintain a healthy weight.
  • Exercise.
  • Consider using a cool gel pillow.
  • Practice relaxation and stress-reduction techniques, such as yoga, acupuncturemeditation, or breathing exercises. Some studies suggest that the slow and steady rhythm of breathing may reduce night sweats and help you get back to sleep.

When to be concerned

People experiencing persistent night sweats should see their doctor for a full exam to determine the underlying cause. Talk with your doctor to learn what might be causing your issues and what steps might best help correct the problem.

About the Medical Reviewer

Ann S. LaCasce, MD, MMSc

Ann LaCasce, MD, MMSc, Associate Professor of Medicine, is a lymphoma specialist and is the Director of the Dana-Farber/Partners CancerCare Fellowship in Hematology/Oncology.  She serves on the Alliance Lymphoma Committee, the National Cancer Comprehensive Lymphoma Guidelines Panel and the Lymphoma Research Foundation’s Scientific Advisory Committee.  

2 thoughts on “Night Sweats: Are They a Symptom of Cancer?”

  1. My father started taking B-12 injections and that stopped both his night sweats and his restless leg syndrome. He’d already been on B-12 tablets. Perhaps they weren’t being metabolized. He did this on his own after hearing that it had worked for a brother-in-law. I don’t know how widely known the connection between low B-12 vitamin and night sweats is; I could find only several posts by one individual when I searched online.

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