Night Sweats

1 Night Sweats Summary

Night sweats, or sleep hyperhidrosis, is a very common complaint characterized by excessive sweating in the night even when the room is cool. This sudden hot flash may often drench the sleepwear and the sheet, causing much discomfort to the person.

Night sweat was found to affect a major part of the population and is often not a cause for concern. It is not a disease in itself but is an indication of an underlying problem. About 75% of women experience night sweats during perimenopause.

Symptoms of night sweats may range from mild to severe and also vary in duration. Some of the most common symptoms of night sweats are heat, irregular heartbeat, flushing, chills, and headache.

Nausea is also seen as an accompanying symptom in night sweat. Other symptoms of night sweats depend on the underlying cause of the condition. This includes fever, unexplained weight loss, and vaginal dryness.

Sweating is the natural way to prevent overheating. This is controlled by the hypothalamus and uses sweat glands to keep the body cool. Sweating is usually triggered by an increase in the body temperature as in a hot day or after a workout.

Certain other conditions are also known to trigger the cooling down procedure by the hypothalamus, this includes: 

Night sweats are treated by primary physicians, gynecologists or internists. When night sweats are caused by underlying conditions it is referred to the concerned specialists for controlling the symptom.

One should visit a doctor if night sweats persist for a long time and interrupt sleep often. Other symptoms like fever and unexplained weight loss also warrant medical check-up to diagnose the underlying condition.

Treatment of night sweat depends on the underlying cause of the symptom. In some cases, the direct cause of night sweating cannot be identified and in such cases, preventive measures are the best option.

Having a healthy, balanced diet is the first among them. Developing good sleep habits like keeping the room cool and wearing light, breathable clothes will be of help. Caffeine, spicy foods and alcohol should be restricted, particularly before going to bed.

Relaxation and breathing exercises help the body to relax and aid in falling asleep. Keeping the body well hydrated is very important in preventing night sweats. Regular physical exercise and maintaining optimum body weight is equally important.

Night sweats caused by medications may improve with changing or discontinuing of the same, which is done after discussion with the doctor. Night sweats caused by infections and some serious conditions cannot be prevented.

Outlook of night sweat treatment depend on the underlying cause and also the health of the patient. Night sweats caused by menopause often improve with time after menopause in women.

2 Causes

Night sweats may be caused by a harmless condition or by a serious underlying cause. Under normal conditions if the room is hot or if the person is using thick or too many bedclothes, it may cause sweating.

This can be differentiated from night sweats and is defined as hot flashes caused by reasons other than overheated environment. In some cases, flushing also resembles a night sweat and is difficult to distinguish. There are multiple causes for night sweats.

Some common causes are: 

Menopause – this is one of the most common conditions that causes night sweats in women. About 75% of women in perimenopausal stage experience night sweats. Hot flashes are common during the menopausal transition and it may occur during the night too. This feature actually precedes menopause and often resolves once menopause is reached.

Idiopathic night sweats – this is a chronic condition in which the body produces increased amount of sweat, but without any identifiable underlying condition or cause.

Infections – several infections have night sweats as one of the symptoms. Tuberculosis is the most common one among them. Some bacterial infections that cause inflammation of the heart valves, bones and abscesses cause night sweats. HIV/AIDS also causes night sweats.

Cancer – one of the earlier symptoms of cancer is excessive sweating in the night. Lymphoma is the most common form of cancer that causes night sweats. In most of the cases, it is accompanied by unexplained weight loss.

Certain medications – certain medications are known to cause night sweats. This includes: 

  • Antidepressants
  • Psychiatric drugs
  • Fever-lowering drugs like aspirin and acetaminophen
  • Drugs that cause flushings like niacin, tamoxifen, and hydralazine
  • Cortisone medications like prednisone and prednisolone

All antidepressants are known to cause night sweats as one of the side effects of the medication.

Hypoglycemia – low levels of sugar in the blood may lead to night sweats. Patients who are on anti-diabetic medications often experience night sweats due to hypoglycemia.

Hormone disorders – Many hormonal disorders are associated with night sweats. Pheochromocytoma, carcinoid syndrome and hyperthyroidism are some among them.

Neurologic conditions -- autonomic dyslexia, post-traumatic syringomyelia, stroke and autonomic neuropathy are some neurologic conditions that increase sweating and cause night sweats.

GERD – this condition is characterized by leaking of stomach acid into the esophagus, and may cause night sweats in some cases.

Obstructive sleep apnea – obstructive sleep apnea is characterized by sudden interruptions in sleep and often lead to night sweats.

Substance abuse – alcohol and drug abuse are known to be associated with night sweats. This is particularly true with the use of the drug, heroin.

Anxiety – problems like stress are known to cause sweats during the day, and in some cases, this may affect sleep too.

The severity and duration of night sweats are increased by certain triggers. This includes environmental triggers like excess bedding, hot showers, warm weather and hot rooms.

Emotional problems like stress, anxiety and some disturbing dreams may also increase the severity of night sweats. Spicy foods, alcohol, caffeine and diet pills are some of the behavioral triggers for night sweats.

3 Diagnosis and Treatment

Persistent night sweats and those associated with symptoms like fever and unexplained weight loss need medical attention.

Family practitioners, internists and gynecologists are the doctors who are consulted for diagnosing and treating this condition. If the underlying cause of night sweats is an infection, an infectious diseases specialist may be consulted.

A detailed medical history and physical examination are the first steps in the diagnosis of the cause of night sweats. These steps will reveal the associated symptoms that will help in the differential diagnosis of the cause of night sweats.

The diagnostic test is usually based on the associated symptoms: 

  • Blood culture, HIV test, complete blood count (CBC) and HIV test are recommended if the associated symptoms are fever, exposure to TB, cough, weight loss, and low immunity
  • Hormonal replacement therapy is suggested if night sweats are caused by menopause
  • Lymph node biopsy is the confirmatory diagnostic test if the symptom associated with night sweat is lymphadenopathy without any recent infection
  • CBC and heterophile antibodies are analyzed for upper respiratory infections
  • Sleep study is recommended for those with excessive daytime sleeping, loud snoring and gasping during sleep
  • Thyroid function tests are suggested if the associated symptoms are tremor and heat intolerance
  • Urine analysis is used to diagnose if the patient has palpitations and labile hypertension
  • Blood culture and echocardiogram are recommended for diagnosing new heart murmurs felt during physical examination
  • Along with the vital signs, the doctor also checks for lymphadenopathy and splenomegaly. Signs of immunocompromised, hyperthyroidism and pheochromocytoma are also noted during the examination.

Treatment of night sweats is based on the underlying cause of the issue. Treating the underlying medical condition resolves night sweats. Thus there is no specific treatment directed to night sweats but focuses on the underlying condition.

Hormone therapy is recommended for night sweats caused by menopause. Estrogen therapy and combined therapy (estrogen and progestin therapy) are used to control this symptom during perimenopause.

Discontinuation or changing the medication that causes night sweats as a side effect is the best way to alleviate the symptom. An alternative medicine or therapy is suggested in the place of the medicine. Night sweats associated with infections, cancers, and some other serious conditions may be difficult to prevent.

When there is no direct cause of night sweats, simple methods will help to manage the problem: 

  • Use light, cotton or non-synthetic, breathable clothes during sleep
  • Keep the room comfortably cool
  • Avoid using thick bed sheets and bundling
  • Have a healthy diet
  • Follow a regular routine of physical activity
  • Practice breathing exercises and relaxation techniques
  • Maintain optimum body weight
  • Avoid spicy and warm food, particularly in the night
  • Keep the body well hydrated

Noting the triggers of night sweats will be helpful in preventing the symptom. Many lifestyle changes, as mentioned above and alternative medicine help in alleviating night sweats to a certain extent.

Massage, aromatherapy, and herbal supplements are used in controlling night sweats. Black cohosh is a common herbal supplement used to control excessive sweating during the night. A combination of herbal supplements and lifestyle modifications are very useful in reducing night sweats.

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