The Leading Causes of Night Sweats and Ways to Deal with It

written by / January 14, 2020
Causes of Night Sweats - Featured

Do you wake up in the night tired and soaked in sweat? The causes of night sweats could simply be due to a bedroom that’s too hot. While the problem is common and associated with a high dose of discomfort, it’s generally harmless. On the other hand, excessive sweating at night and waking up to a wet pillow in the morning may mean you should consult a doctor. There may be an underlying health condition that needs to be addressed.

Why Do I Wake up Drenched in Sweat at Night

More commonly known as night sweats, the medical names for the condition are hyperhidrosis, and nocturnal hyperhidrosis, categorized according to the International Classification of Diseases (ICD-10, version 2007). It’s a disorder presented as profuse sweating during a patient’s sleep pattern. However, sometimes it occurs in individuals during the day. There are various known night sweat causes, and the condition is observed most commonly in adulthood, but it can affect any age. 

Perspiration or sweating is an essential function of the body for thermoregulation and is controlled by thermosensitive neurons in the hypothalamus. To get highly technical, as the body temperature rises, the autonomic nervous system stimulates the extrinsic sweat glands to release the fluid. This fluid contains 0.2%–1% solutes, including sodium chloride, urea, and lactate. Sweat glands are paradoxically innervated by sympathetic “cholinergic” neurons, which are the only ones that secrete acetylcholine.  

Considering these complex biological processes, can stress cause night sweats? Increased sweating is triggered under normal physiological conditions like high ambient temperatures, intense physical exertion, and the consumption of nutritious foods. However, intense emotional stress such as anger, rage, panic attacks, etc., can also lead to excessive sweating. 

Types of Night Sweats

There are primary and secondary hyperhidrosis. Primary or idiopathic hyperhidrosis has no clear origin, though it can be inherited genetically. It’s characterized by excessive sweating during the day, typically affecting the feet, palms of the hands, and armpits. This type of sweating affects about 1%–2% of the population. It usually occurs around puberty, and it’s been known to cause psychological discomfort. 

When the cause of night sweats is associated with abnormal conditions and pathological processes, it’s more precisely defined as secondary hyperhidrosis, because the sweating crosses beyond what’s required to regulate body temperature. This is the sign of another, underlying condition. 

Sweating Sickness 

It’s interesting to note that in the history of medicine, one of the most lethal infectious diseases, called “sweating sickness,” appeared in England and Europe in five epidemics between 1485 and 1551. The reasons for night sweats associated with this mysterious disease remain unknown. 

In modern scientific literature, physicians still debate different hypotheses about the probable cause of this condition, which led to the deaths of several thousand people. The disease was characterized by severe sweating, dizziness, headache, myalgia, palpitations, thirst, delirium, agony, and death. Patients who died from it typically met their fatal end only twelve hours to one day after the onset of the dramatic symptoms.

When Should I Be Worried About Night Sweats? 

As a rule, patients likely have night sweats if they regularly wake up with wet bed linens and sheets—in the absence of external circumstances such as having a high room temperature or sleeping under excessive blankets or in too much clothing.

Hyperhidrosis affects about 3% of the population and can be a sign of serious illness. In an Australian survey, 40% of women reported having had night sweats at least once in the month before being surveyed. As a note, regarding the occurrence of night sweats, men and women are both affected.

Although the condition is common, it’s considered harmless on its own. On the other hand, excessive night sweats signal the presence of an underlying illness. Regular and excessive sweating requires a mandatory medical consultation to rule out a possible underlying illness. This is especially the case when the night sweats occur in combination with fever, fatigue, lack of appetite, sudden weight loss, cough, and other associated night sweats symptoms. In fact, specialists recommend consulting a doctor, even when the excess sweating is related to menopause. 

However, an accurate diagnosis can’t be expected after a single visit to the doctor. The medical specialist will first need to go through a patient’s medical history and then evaluate the need for additional studies—which may include blood tests (i.e., glucose level or hormones), even X-rays, and tomography. An osteopathic doctor is also occupied in this field, but remember that you need professional medical advice for most of the health problems associated with night sweats.

What Is the Main Reason for Night Sweats? 

The presence of other complaints, such as an increased incidence of infections, fever, unexplained fatigue, or weight loss, is alarming, and physicians and specialists should assess a patient’s health status. It’s easier to diagnose the primary condition and resolve the problem when you know the different conditions that can cause it.


Causes of Night Sweats - Nightmares

This is one of the most common causes of night sweats. In this case, a person may be completely healthy despite sweating while sleeping—however, they may experience nightmares or they’ll talk or walk in their sleep. However, if you continuously have nightmares, see a doctor to find the cause of your stress. Also, use cotton sheets and put on pajamas made from breathable materials.

Menopause and Perimenopause

The hallmarks of menopause include the presence of hot flashes, vaginal dryness, irritability, and anxiety in women around 50. Thus, in the case of night sweats, women of this age group experiencing this symptom may be entering menopause.


This is a condition characterized by lower testosterone levels, most pronounced after the age of 50, and also associated with the onset of night sweats. Although andropause occurs in men over 40 or 50 years of age, it can also affect younger men. Reduced amounts of other male hormones during andropause is one of the most frequent causes of night sweats in men

Infectious Diseases

A fever can be a sign of an infection. Tuberculosis and brucellosis are among the most common causes of profuse night sweating. Endocarditis (inflammation of the heart valves), osteomyelitis (inflammation of bone structures), the presence of abscesses (of the appendix, tonsils, diverticulitis, etc.), sepsis, and immunodeficiency states (including HIV) may cause excessive night cold sweats

HIV/AIDS could be a reason for the occurrence of infections and tumors, which are also a reason for night sweats. Respiratory diseases often cause sweating, as do pneumonia—and inflammation in the lungs caused by infection (bacteria, viruses, etc.) is associated with nocturnal hyperhidrosis.

Endocrine Disorders

Pheochromocytoma (adrenal formation), carcinoid syndrome (a formation in the lungs or gastrointestinal tract leading to hormonal production), and hyperthyroidism are all examples of disorders of the endocrine system. These disorders represent some possible causes of night sweats. 

Hyperthyroidism is an abnormal state of the thyroid gland with the hypersecretion of thyroid hormones—thyroxine (T4) or triiodothyronine (T3)—and the corresponding increase in blood with the onset of thyrotoxicosis, accompanied by an accelerated metabolism. Pheochromocytoma is a benign neuroendocrine tumor of the adrenal gland that secretes increased amounts of catecholamines, usually norepinephrine, and less adrenaline (epinephrine); it’s also one of the known causes of severe night sweats. 

Diabetes (type 1 and type 2) and low blood glucose, sometimes called nocturnal hypoglycemia, can manifest as a nighttime cold sweat and unpleasant headaches. Most people worry when their blood sugar jumps, but they don’t realize that low levels are even more dangerous. If glucose levels are too low, there’s a risk of coma and even death if untreated. 

These conditions are all examples of the severe and life-threatening causes of undiagnosed night sweats.


Also, associated with night sweats, cancer, most notably lymphoma and leukemia, also produces this symptom. Its occurrence is usually related to the presence of other signs, including severe weight loss, fever, anorexia, fatigue, dyspnoea, etc. 

Night sweats are also one of the early and dominant symptoms of lymphoma (cancer of the lymphocytes of the immune system), along with the appearance of other symptoms. In some patients with Hodgkin’s disease/lymphoma, however, night sweats might be the only complaint. 

Night sweats and cancer are known to go together. Acute myeloid leukemia and other malignant neoplasms and cancers (liver, breast, bone, etc.) are also associated with nocturnal hyperhidrosis. In addition, some types of cancer treatment can also cause night sweats and fever.

Gastroesophageal Reflux Disease

Here, the stomach acids enter the esophagus causing severe discomfort and a feeling of burning behind the sternum. This disease, although rare, can be a cause of night sweats in men and women.

Neurological Disorders

Some specific neurological problems, as well as psychological conditions that affect the autonomic nervous system, may be related to hyperhidrosis. The increased sweating associated with a hypothalamic syndrome, damage of the central nervous system, autonomic neuropathy, post-traumatic stress, chronic fatigue syndrome, stroke, and syringomyelia are all among the causes of night sweats and chills.

The Use of Certain Medications

Hyperhidrosis may be a side effect of medication. When this happens, it’s necessary to adjust the dose or change the drug after consulting with a doctor. 

The most common drugs prescribed for depression—tricyclic antidepressants, serotonin reuptake inhibitors, and hormonal drugs used in the treatment of some cancers, including prostate cancer—are among the most common causes of night sweats. Of most antidepressants, 8%–22% produce hyperhidrosis as a side effect. Antipyretics (aspirin, acetaminophen), corticosteroids (prednisone and prednisolone), high doses of niacin (vitamin PP), and nitroglycerin have a similar impact on increasing night sweats.

Addiction (Alcohol, Opiates, or Narcotics)

The intake of considerable amounts of caffeine, alcohol, nicotine, and opiates or narcotics, including heroin, can also cause hyperhidrosis. Withdrawal from ceasing the use of drugs, sedatives, and alcohol may be causes of hot flashes and night sweats. Addiction to alcohol is on the increase, thus causing even more health problems.

Drinking Alcohol at Bedtime

Causes of Night Sweats - Alcohol

Drinking alcohol before sleeping or in the late hours of the night can impair the mechanisms of thermoregulation. Therefore, not only can night sweats occur, but they can also lead to severe disturbances in one’s quality of sleep.

Anxiety Disorders

Associated with night sweats, anxiety is prevalent these days. It’s well-known that some mental problems present with physical symptoms. In line with this, it’s fair to say that night sweats can happen because of anxiety or stress—especially if you also experience worry, dread, and fear or have sleep issues or nightmares, feel irritable, or have other mood changes. It’s recommended to seek medical help because this condition may worsen over time.

Autoimmune Diseases

Autoimmune conditions and overlap diseases aren’t the most common cause of night sweats, but night sweats do accompany most of them. Rheumatoid arthritis, celiac disease, systemic lupus, and multiple sclerosis all share the symptoms of night sweats, fever, and hot flashes.

However, sometimes the unspecific clinical picture of the overlap of symptoms makes it challenging to establish the right diagnosis.

Excessive Sweating During Pregnancy

Due to the hormonal changes that occur, one of the common causes of night sweats in women is pregnancy. This unpleasant experience only adds to the general difficulty women have trying to sleep during pregnancy.

Obstructive Sleep Apnea

This condition is characterized by short-term pauses in one’s breathing during sleep, and it affects about 4% of middle-aged men, with more occurrences in overweight individuals. Non-controlled and untreated sleep apnea can often result in nocturnal hyperhidrosis.

How Can I Stop Night Sweats Naturally? 

The treatment of night sweats depends on the underlying causes. If they’re due to a bacterial infection, for example, it’s reasonable to have antibiotic therapy prescribed. To relieve the symptoms of menopause, your doctor may recommend a special diet, the intake of nutritional supplements, hormone replacement therapy, and certain medications according to your condition. When sweating is the result of a more severe illness, treatment could be more complicated.

Certain factors that are identified as the main causes of night sweats can serve as a starting point in controlling the condition, in addition to treating the underlying cause, when it’s known. Amongst them are the following:

  • Exercising before bedtime
  • Drinking warm drinks before bed
  • Increased alcohol consumption before falling asleep
  • Eating spicy foods in the evening
  • Adjusting the heater in the bedroom to higher than the recommended level
  • Lack of air conditioning during hot seasons
  • Unsuitable bed linen for the season—especially in the spring when temperatures rise but winter blankets have not yet changed

Although the practices mentioned above won’t be the causes of extreme night sweats, they still contribute to increased sweating at night. If there is no specific reason for excessive sweating, treatment is based on prevention. 

For the best ways to treat night sweats, you could also implement some of these tricks:

1. Take care of your sleeping environment.

To help ease your primary health condition, making sure that you keep your sleeping area well-ventilated before bed is considered an effective night sweats treatment. It’s necessary to have access to fresh air in the bedroom—in the summer, sleep with an open window. It is also essential that the room temperature be lower than the rest of the home. If you need to adjust this, run the air conditioner for a while before going to bed.

2. Bed linens should be made of light and natural fabrics, like cotton or satin. 

One of the simpler causes of night sweats comes from using denser fabrics in warmer temperatures. In the summer, the fabric should be more slack and breathable. Cotton sheets characterized by a thread count of 400, approximately, will keep you cool and prevent any bacteria from growing in the sweat. Higher thread counts are also moisture-wicking, but they’re less breathable, also due to their higher thread count.

This can answer the question, “Why do I sweat in my sleep when it’s cold?” If you wake up at night soaked in sweat or feel too hot even when the room temperature is cool, try sheets in the 400–500 range to improve the sensation. If you feel warm and comfortable, you can sleep without a blanket, but beware of the cold, especially with an open window.

3. Be aware of what you eat and drink in the evening.

Sometimes one of the reasonable causes of night sweats is what you consume before bed. So try to have dinner up to four hours before bedtime, avoiding spicy dishes and products. Avoid drinking alcohol or caffeine or taking antidepressants. Don’t eat within three hours before bedtime.

4. In any case, try to combat stress.

Add relaxation activities to your schedule or plan a particular time to practice relaxation. Indulge in more time for rest. Deep breathing techniques and some yoga practices are also helpful. Instead of television, read your favorite relaxing book. All of these could help your symptoms.


What can night sweats mean?

If you wake up in the morning soaked in sweat in your sheets, this could be a sign of a medical problem. It may not by a mere uncomfortable, unpleasant situation. Most people link night sweats with hot temperatures, but this can be due to serious health problems, some of which can even be life-threatening. If the condition continues for more than three months, see your doctor.

Can high blood pressure cause night sweats?

People with high blood pressure may experience sweating—both at night and during the day—among other possible symptoms. Signs such as nervousness, difficulty sleeping, or facial flushing can accompany the condition. However, high blood pressure is detected by measuring it. Extensive sweating that lasts for several weeks, when it isn’t caused by environmental factors, also requires medical advice.

What kind of cancer makes you sweat at night?

Night sweats, in combination with unexplained weight loss and fevers, are early signs of some cancers. The most common type of cancer associated with night sweats is lymphoma. Other cancers related to the symptom of night sweats are leukemia (i.e., acute myeloid leukemia), liver cancer, breast cancer, bone cancer, etc.).


There are many simple reasons someone might wake up with sweaty sheets. Whatever an individual’s causes of night sweats seem to be, sweating is a symptom that needs to be weighed well before being considered in a medical diagnosis. If the night sweats signal a health problem, the central health issue must be addressed. If they’re the result of bad sleeping habits, then better sleep hygiene needs to be adopted.

At medical school, it was easy to realize that sleep is crucial while studying during the many sleepless nights I spent. As a new mom, when the lack of sleep became even more evident, this was the real moment when I started appreciating the benefits of a good night’s sleep. Since sleeping is so essential to our health and immune system, I took it upon myself to educate people on different aspects of sleep by sharing the valuable information I have learned.

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