The Causes of Night Sweats and Hot Flashes
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The Causes of Night Sweats and Hot Flashes

Night sweats may seem harmless, but it really does depend upon the reason you are having night sweats. Night sweats are excess sweating which occurs at night when you are sleeping

Night sweats may seem harmless, but it really does depend upon the reason you are having night sweats. Night sweats are excess sweating which occurs at night when you are sleeping. Some people wake up and their body, bedding, and bed is soaked. Night sweets are common enough and it could be caused by a room that is too hot or because someone is wearing too much clothing, but it could be other things as well. Doctors will make a distinction between being too hot because of a room that is too hot, or wearing too much clothing to bed, and being too hot because of a medical condition. Menopausal women know the classic medical term for night sweats associated with menopause. Doctor will call this type of severe night sweat hot flashes.

What causes these night sweats – hot flashes

Of course the doctor is the best one to determine what causes night sweats or hot flashes. The doctor would normally take a full medical history of the patient to know what is possibly going on.

Menopause and Perimenopause

Women who are entering the stage of their lives where the production of the ova declines and the menses begins to lessen (perimenopause) or ends completely (menopause) will be among the population most affected by night sweats – hot flashes. These symptoms as well as many others, can continue for several years during the perimenopausal phase of a woman's life before the complete cessation of menses.

Idiopathic hyperhidrosis

Idiopathic hyperhidrosis is a chronic medical condition without any known cause to date. For some reason the body produces way too much sweat.

Infections and night sweats

Doctors have long known that night sweats is a symptom of tuberculosis, however bacterial infection can cause night sweats as well. Some known bacterial infections that cause night sweats include:


Endocarditis is the inflammation of the lining of the valves of the heart


Osteomyelitis is the inflammation inside the bones which is caused by some kinds of infection


Tonsil abscesses, boils, appendix, perianal, peritonsillar which is an abscess next to the anus, and diverticulitis which is the eruption of the diverticuli ( small pouches or sacs that attach to the colon or intestines).


The most common cancer associated with night sweats is lymphoma, but there could be other forms of cancer where night sweats including fever and weight loss, would be one of the early symptoms.


Where a tumor or an infection cannot be determined to be the cause of night sweats, doctors often look towards medication as the next most probable cause.

The types of medications which are most common to night sweats are:

  • Antidepressants such as selective serotonin reuptake inhibitors (SSRIs), venlafaxine (Effexor) and bupropion (Wellbutrin) can be the cause of night sweats. About 8 to 22 percent of people taking these antidepressants complain of night sweats.
  • Anti-psychotic medication also produce the side effect of night sweats
  • Over the counter medications
  • Night sweats can be a side of effect of over the counter medication such as aspirin or acetaminophen when they are proscribed for fever. 

There are certain drugs that cause a red flushing of the skin (an entirely different symptom) and are often confused for night sweats. These particular drugs include:

Niacin (Niacor, Niaspan, Slo-Niacin) for lipid disorders, tamoxifen (Nolvadex), sildenafil (Viagra), hydralazine, and nitroglycerine. Cortisone, and prednisone may also cause night sweats.


Individuals who take anti-diabetic medication or insulin may suffer from night sweats due to the low blood sugar level.

Hormones and night sweats

Different hormone conditions such as pheochromocytoma, (tumor of the adrenal glands that releases epinephrine and norepinephrine, adrenaline) hyperthyroidism (overactive thyroid), and carcinoid syndrome (caused by hormones released by the carcinoid tumor), may cause night sweats.

Certain neurological conditions and night sweats

Though not altogether that common, certain neurological conditions such as stroke, autonomic dysreflexia (over-stimulation of the automatic nervous system usually triggered by a spinal chord injury), post-traumatic syringomyelia ( a fluid-filled cyst on the spinal chord) or automatic neuropathy ( disease of the nerves) can cause night sweats.


Even though night sweats may seem harmless enough if they occur quite frequently, let your doctor know so that he or she can determine if there may be an underlying medical condition which are causing them.


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Comments (8)

Certainly not my favorite thing, and some of those reasons for night sweats is pretty frightening.

Ranked #1 in Sleep

yep some of these underlying causes are scary, I had no idea about the cancer , always knew about the hormones

Ranked #9 in Sleep

I have read that alcoholics or someone who has been drinking too much alcohol like a drinking binge can get night sweats once they stop drinking alcohol.

Ranked #1 in Sleep

yeah I think that is part of the DT's

An in depth analysis of night sweats and hot flashes, Carol

Very detailed facts and useful Carol, thanks a lot.

Good discussion here Carol. Nope, no night sweats for me ... yet but hoping never, thanks.

Ranked #1 in Sleep

thanks deep blue, ron and phoenix, actually deep blue I am covering every aspect of sleep and dreams that I can think of because you asked lol