Sweating is necessary to regulate your body temperature. But if you regularly wake up with soaked sheets, you suffer from night sweats, and it may be desirable to consult a doctor to determine the cause of this excessive sweating.

Possible causes of excessive sweating

Thyroid Disorders

One of the causes of these night sweats could be your thyroid gland, that tiny butterfly-shaped gland located at the base of the neck. The excessive production of the hormone thyroxine causes hyperthyroidism which stimulates the metabolism.

This quickening of the metabolism can trigger nighttime sweating and other symptoms, such as increased appetite, tachycardia, or unintentional weight loss. This disorder is easily revealed by a blood test.


Night sweats in people with type 1 diabetes may indicate low blood sugar or hypoglycemia. This causes the secretion of epinephrine (or adrenaline), which is the stress hormone that can cause sweating.

It can also be the result of an incorrect dosage of insulin at bedtime. You can temper these episodes of nighttime sweating with preventative measures such as a bedtime snack, which aims to balance your insulin levels.


The sweating caused by stress is different from that resulting from physical exertion. It is produced by the apocrine sweat glands in the armpits, groin, and scalp.

When you are very hot, other glands can also release sweat. To help ease relaxation from anxiety, try yoga, deep breathing exercises, or meditation before bed. Focus on relaxation and rest to get your sweat glands to follow suit.


Infections, especially tuberculosis, can cause nighttime sweating. According to the Canadian Department of Public Health, this illness is often accompanied by fever that triggers night sweats and chills, loss of weight and appetite, and a cough that can last for more than three weeks.

Other infections of bacterial origin, osteomyelitis (inflammation of the bones and bone marrow), and endocarditis (inflammation of the heart valves) are sometimes the cause of such sweating.


Almost 85% of postmenopausal women experience hot flashes. During this time, the levels of estrogen and progesterone, the hormones that maintain body temperature, fluctuate, causing these hot flashes.

Place a fan next to your bed and turn it on when they happen or try absorbent pajamas (like Cool-jams), designed to keep postmenopausal women dry overnight.

Premenstrual Syndrome (PMS)

Younger women may also experience night sweats due to the same hormones as postmenopausal women. Researchers have noticed that women who are in their luteal phase, which is the second phase of the menstrual cycle and the peak of PMS, sweat more than during the first phase of their cycle.


The glass of wine that relaxes you before bed can also cause you to wake up in a profuse sweat. Alcohol can interfere with the nervous system and the body’s ability to regulate and control its temperature, according to several health sites.

It can cause the diameter of the vessels to increase due to dilation (vasodilation) and make you feel like a furnace.


Certain antidepressants, like selective serotonin reuptake inhibitors (SSRIs), and those for diabetes like metformin, can cause night sweats, according to the Mayo Clinic.

Over-the-counter medications such as naproxen, a pain reliever, can also have this effect. The International Hyperhidrosis Society has compiled a comprehensive list of prescription drugs that can lead to night sweats.

Sleep Apnea

Obstructive sleep apnea (OSA) is a breathing defect that causes muscles in the throat to relax and the airways to block, the Mayo Clinic explains. This results in respiratory arrest during sleep. The extra effort to catch your breath can cause you to wake up with your face on fire and your body bathing in sweat.

One study reports that 30% of men and 33% of women who do OSA reported night sweats compared to 9% of men and 12% of women in the general population.


Sometimes night sweats are just the result of your heavy coffee consumption. Caffeine is a mild stimulant that can excite the central nervous system, especially in postmenopausal women.

Research has shown the stimulating effect caffeine has on their night sweats and hot flashes.

Lower your dose if you notice these other symptoms of drinking too much coffee.

Low testosterone in men

There is a treatment for prostate cancer that causes hot flashes in 80% of patients. It is done by androgen deprivation which lowers the levels of testosterone, the male sex hormone.

Experts from Harvard Health report that researchers suspect the heat is the result of intervention by the thermal control center of the hypothalamus, which is part of the nervous system in the brain. It would send signals that cause the blood vessels in the skin to dilate leading to a feeling of heat similar to that of menopause.

Yes, men have their “PMS”. This is one of those incredible facts that seem wrong but are true!

Gastroesophageal reflux disease (GERD)

Little is known about the link between the heartburn that accompanies GERD and night sweats. However, a study did find it. She testifies from a significant number of patients treated for GERD who have had relief from their night sweats with this treatment.

Chronic fatigue syndrome

Myalgic encephalomyelitis (chronic fatigue syndrome) is often accompanied by night sweats. Night sweats are often reported in the early stages of the disease or during relapse, according to the American Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Society. Sweating can be caused by an activation of the immune system, by hormonal imbalance (especially during menopause), or by hypoglycemia.


Lymphoma is cancer of the lymphatic system. One of the symptoms, Lymphoma Canada says, is heavy nighttime sweating. It comes with many more, including fatigue, weight loss, and shortness of breath. If you have this array of symptoms, see a doctor before making your own diagnosis.

How to avoid of night sweats

The treatment of night sweats consists mainly in eliminating the cause. If no medical explanation is identified, here’s what you can do to sweat less at night, and therefore sleep better.

  • Avoid alcohol, caffeine and drugs.
  • Maintain a healthy weight
  • Adjust your sleep habits: remove excess blankets from your bed, change duvets (lower stocking density), discover yourself or open a window in your room. It can also be helpful to use air conditioning, a fan, or find a cooler place to sleep.
  • Eliminate stress: exercise during the day to fall asleep more serenely.
  • Avoid spicy foods and hot drinks just before bedtime. Foods that contain tryptophan like figs, dates, banana and yogurt have a positive effect. This amino acid is converted into serotonin and melatonin. It is this last substance in particular that makes us drowsy.
Jenny Zhang

Jenny holds a Master's degree in psychiatry from the University of Illinois and Bachelors's degree from the University of Texas in nutritional sciences. She works as a dietician for Austin Oaks Hospital in Austin, Texas. Jenney writes content on nutrition and mental health for the Scientific Origin.