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If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.
Night sweats are episodes of excessive sweating (hyperhidrosis) that occur during sleep; they are generally not due only to a warm room, heavy pajamas, or too many blankets. During these episodes, you may find yourself waking up in sweat-drenched bedclothes. Night sweats tend to occur repeatedly, although there is no standard definition of how severe or how often the sweating occurs. Estimates for how many people suffer from night sweats range from 10–41%; it is a common, and often uncomfortable issue affecting many people (Mold, 2012).
What causes night sweats?
While night sweats are not necessarily a cause for concern, they may be a sign of an underlying medical condition or a side effect of certain medications.
Hormone disorders are common causes of night sweats, including:
- Menopause: Night sweats (and hot flashes) are common in women going through menopause, as well as women who are near menopause (perimenopause), due to hormonal changes. If you have irregular or absent periods, are around age 50, and have no other symptoms, then menopause may be the cause of your night sweats. Up to 80% of women in menopause report some symptoms of night sweats and hot flashes; symptoms can begin years before the periods stop (Harlow, 2020).
- Thyroid abnormalities: Thyroid problems, especially an overactive thyroid (hyperthyroidism), can lead to night sweats.
- Pregnancy: Pregnancy and its associated hormonal changes can lead to night sweats.
- Adolescence: Puberty is characterized by fluctuating hormones and resultant changes in the body; night sweats may accompany this process
- Diabetes: People with diabetes may experience low blood sugar (hypoglycemia) at night; when this happens, it can cause night sweats (Viera, 2003).
- Endocrine tumors: Tumors that produce excess hormones, like pheochromocytoma and carcinoid tumor/carcinoid syndrome, can cause night sweats by affecting the normal balance of hormones.
Infections are another night sweat trigger; common culprits include human immunodeficiency virus (HIV), tuberculosis (TB), infections of the lining of the heart (endocarditis), and bone infections (osteomyelitis), infectious mononucleosis, and bacterial infection causing an abscess (pus-filled pocket).
Other common causes of night sweats include certain cancers (like leukemia and lymphoma), gastroesophageal reflux (GERD), anxiety disorders, autoimmune disorders (like rheumatoid arthritis and giant cell arteritis, obesity, sleep disorders (like obstructive sleep apnea), stroke, substance abuse (like alcohol or benzodiazepines) (Mold, 2012).
Many of these medical conditions that cause night sweats are also accompanied by other symptoms like unexplained weight loss, fevers, hot flashes, etc.
Hypospadias: urethral opening misalignment
In addition to medical conditions, certain medications can also cause night sweats as a side effect; these medications include (Viera, 2003):
- Antidepressants, like venlafaxine (see Important Safety Information)
- Diabetes medications
- Hormone therapy
- Drugs used to treat fevers (antipyretics) like acetaminophen and aspirin
Sometimes all potential causes get ruled out, and no specific cause can be found; this is called “idiopathic” night sweats, meaning there is no known cause for your excessive sweating.
How to diagnose the cause of night sweats
Diagnosis of night sweats begins with a discussion with your healthcare provider about the severity, frequency, and any associated symptoms you may have with your night sweats. A physical exam may further narrow down potential causes to allow for a more focused work-up. As mentioned above, night sweats can be a symptom of an underlying medical condition, and your provider will look for other symptoms like hot flashes, abnormal periods, fevers, cough, unexplained weight loss, heartburn, and snoring. Tell your provider if you have a history of medical conditions like diabetes, HIV, substance abuse, obstructive sleep apnea, hyperthyroidism, or anxiety disorders. In some cases, additional testing like bloodwork or chest x-rays may be indicated.
Treatment of night sweats
The best way to treat night sweats is to determine the underlying cause and address it. The following is a summary of potential treatment options depending on the cause of the night sweats.
Adjusting sleep habits may help, regardless of the cause. Lowering the temperature of your bedroom at night, wearing lighter sleepwear, using lightweight covers, etc. may help with the night sweats.
- Harlow, S. D., Elliott, M. R., Bondarenko, I., Thurston, R. C., & Jackson, E. A. (2020). Monthly variation of hot flashes, night sweats, and trouble sleeping. Menopause, 27(1), 5–13. doi: 10.1097/gme.0000000000001420, https://www.ncbi.nlm.nih.gov/pubmed/31567864
- Mold, J. W., Holtzclaw, B. J., & Mccarthy, L. (2012). Night Sweats: A Systematic Review of the Literature. The Journal of the American Board of Family Medicine, 25(6), 878–893. doi: 10.3122/jabfm.2012.06.120033, https://www.ncbi.nlm.nih.gov/pubmed/23136329
- Viera, A. J., Bond, M. M., & Yates, S. W. (2003). Diagnosing Night Sweats. American Family Physician, 67(5), 1019–1024. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/12643362
Dr. Mike is a licensed physician and the Director, Medical Content & Education at Ro.