Many of us have experienced it before, and some of us frequently:  awakening in the middle of the night drenched in sweat.  The bed sheets are soaked through; you feel this strange, uncomfortable sensation of being hot and cold at the same time.  You may need to take a shower to wash off all the mess.  WTH?

There are numerous potential reasons why you might sweat substantially at night.

1.  The room’s too hot.  It’s a painfully obvious cause, but a very common cause nonetheless.  Some couples disagree about how warm or cool the bedroom should be at night; you might be surprised by how often this problem occurs, and how bitter the disagreements can become.  In addition, many people simply “run hot” at night and prefer to sleep in a very cool, or even downright cold, environment.

2.  Infections.  A whole host of different viral, bacterial, and fungal organisms, most commonly causing upper respiratory tract infections and the flu, can cause fever and sweating.

3.  An underlying medical disorder.  Conditions that may be associated with night sweats would include certain cancers, thyroid problems and other endocrine abnormalities, a few neurologic disorders, and hypoglycemia related to diabetes medications.  Some medications, such as aspirin, acetaminophen, and some antidepressants, can also be associated with night sweats in and of themselves.

4.  An underlying sleep disorder.  Obstructive sleep apnea often causes “sympathetic overactivation,” triggering constant surges of adrenalin and other hormones in your bloodstream at night, leading to sweating.  The restlessness and physical activity associated with frequent arousals due to the breathing pauses also frequently contribute to the tendency toward night sweats.

5.  You are in or approaching the “change of life.”  Those hot flashes that accompany menopause can be very bothersome at night, potentially leading to substantial sleep disruption and in some cases chronic insomnia in women.

6.  Stress.  Increased sympathetic activity may also be to blame for an association between stress and sweating at night.

7.  You just sweat a lot, and it’s not clear why.  “Idiopathic hyperhydrosis” means that you simply sweat profusely, and diagnostic testing does not reveal a specific underlying medical reason for it.

What to do about the night sweats, then, depends in large part on the underlying cause(s).  Here are some general suggestions, however.

Sleep in a cool, comfortable, dark environment.  Use bedding materials and clothing that are comfortable and that don’t trap moisture.  See your physician if there is the potential for a concern for an underlying medical problem (weight loss, substantial fatigue, and fever, for example, should prompt you to consider medical attention).  Your primary care physician should be alerted to symptoms consistent with menopause.  If you snore loudly, gasp out of sleep, have witnessed breathing pauses during sleep, and feel tired and sleepy during the day, I would recommend seeing a doc like me, someone who specializes in sleep medicine.