About two or three times a year, I wake up soaked in sweat. There’s enough water that it feels like someone dumped a glass of water over the sheets and the mattress is fairly wet.
Several other times per year, I’ll notice that I wake up and I’ve sweated enough that I can’t get back to sleep (mostly because the sheets are freezing cold), but it’s not as bad as the first instance.
What causes night sweats?
Just a WAG but you probably had a bad dream and failed to remember that you had it. The sweat caused by the fear experienced in the dream.
Intermittent night sweats, such as you describe, could be due to simply having too many blankets and, I suppose, a nightmare. They may also represent a breaking fever (see below). If you are 50’ish year old woman, of course, they may reflect menopause.
Ongoing night sweats, on the other hand, are often a symptom of a serious illness. Things like cancer (especially lymphoma), infections (classically TB, but any will do), and some miscellaneous causes can be responsible.
By and large, drenching night sweats, fevers, and chills are related, and any one should be taken as indicating the presence of the others (even if they weren’t noticed).
Most medical students cannot answer the following question: What is the correct sequential relationship between sweats, fevers, and chills?
[Hey, how do you make spoiler tags? I thought I knew, but apparently not. So, answer to follow in a while]
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Ah, thanks!
[spoiler]The correct sequence is chills (also called rigors), then fever, and finally the sweating.
The chills represent your body’s attempt to generate heat (in response to a signal from the brain or directly as a result of substances produced by the infecting agent or tumor). Once you’ve reached the ‘desired’ temperature, you stop shaking and the fever is apparent. When your body feels it’s time to get its temperature back to normal, it loses heat by sweating (evaporative cooling). [/spoiler]
Until I got pregnant, I woke up freezing and shaking and drenched in sweat every night for more than a year. My room is cool, my bedding is light. My doctor had no explanation. I’d be curious to know what possible causes there may be in the absence of any known illness as well.
Other causes that, IMHO, are important are:
Here you go. Everything you ever wanted to know about night sweats. (Personally, I would caution against putting too much into isolated case reports. Without knowing how many cases did not have the phenomenon, and hence were not reported, it’s impossible to know if the relationship is real)
Anecdote warning:
Whenever I take benadryl before going to bed, I get those awful night sweats. Taken any bedtime medication lately? Remember, most OTC sleeping meds have the same active ingredient as Benadryl.
Sometimes when I get really drunk I wake up in the middle of the night covered in sweat. Never any other time when there isn’t, say, too much heat or anything.
For years, I used to wake up almost every morning completely drenched from my head almost down to my waist. The pillow and sheets would also be drenched. I wondered about all sorts of medical possibilities, but eventually ruled them all out.
A couple years ago the night sweats spontaneously stopped. There was no corresponding change in my health, diet, sleeping habits, environmental factors, etc. I never found out what caused the sweats or why they stopped.
I also used to be much less tolerant of heat in general, and that’s also changed.