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Causes of Night Sweats

Khushnuma Irani
If your bed and clothing often get soaked in sweat while you are asleep, you are probably experiencing sleep hyperhidrosis, more commonly known as night sweats. This condition causes general discomfort and occurs due to many reasons.
Night sweats or sleep hyperhidrosis is a condition that affects a person in the middle of the night or at any time during sleep, even when the indoor temperature is not high. People suffering from it often wake up from a deep sleep, feeling extremely hot or clammy due to excessive sweating.
The situation can be annoying as it disrupts one's sleep and often leads to insomnia and stress. It is important to distinguish flushing from true night sweats, because the same person who perspires heavily at night (or whenever asleep) may be perfectly normal during the daytime.

Types of Sleep Hyperhidrosis

Hyperhidrosis is categorized into primary and secondary hyperhidrosis. In case of primary or focal hyperhidrosis, sweating is localized. On the other hand, secondary hyperhidrosis is characterized by generalized sweating that is caused due to a medical condition or the use of certain drugs. Thus, the doctor has to perform certain tests for ascertaining the underlying cause.
Night sweats can start any age, but they are most common in early adulthood. This condition could even be idiopathic. Idiopathic hyperhidrosis is a condition where the body sweats excessively without any known medical or environmental cause.
The body produces more sweat than is considered normal (on the scalp, hands, feet, underarms, etc). Therefore, if you experience night sweats, do not try to self-diagnose the problem. It is always best to consult a doctor.

Why People Experience Night Sweats

Night sweats can result from a myriad of factors, and those that have been identified by medical experts are as follows:

Environmental or External Factors

Sleeping on an unclean, cluttered bed, with too many blankets in a non-ventilated room can lead to excessive perspiration.

Infections

Tuberculosis patients are particularly susceptible to night sweats. If excessive sweating is accompanied by weight loss, chronic pneumonia, fever, and cough, you should get yourself tested for TB. Other infections that can trigger sleep hyperhidrosis may include:
  • Inflammation of the heart valves (endocarditis), bladder (cystitis) or bones (osteomyelitis) due to a bacterial infection.
  • Histoplasmosis (Cave's disease), which is a fungal disease that often develops in AIDS patients.
  • Abscess of the spleen, lung, or liver (pyogenic liver abscess).
  • Any infection which leads to a fever.
  • Brucellosis (a bacterial infection), infection by Mycobacterium avium complex (MAC, a group of genetically related infectious bacteria), infectious mononucleosis (a viral disease caused by a type of herpes virus), and coccidioidomycosis (a fungal infection, commonly known as valley fever).

Other Disorders/Diseases

Any of these can be a cause for night sweats:
  • Myelofibrosis (disorder of the bone marrow)
  • Diabetes insipidus
  • Prinzmetal's angina (a kind of cardiac chest pain)
  • Chronic fatigue syndrome (mostly affecting women of age 30 - 50)
  • Granulomatous disease (a group of hereditary diseases affecting the immune system)
  • Chronic eosinophilic pneumonia (accumulation of eosinophils in the lungs)
  • Lymph node hyperplasia (rapid growth of normal cells that resemble lymph cells)
  • Acromegaly (production of excess growth hormone by the pituitary)
  • Gastroesophageal reflux disease (GERD) (may also lead to salivation)
  • Ulcerative colitis
  • Diabetic neuropathy
  • Pulmonary edema (generally caused by heart failure)
  • Crohn's disease (an inflammatory bowel disease)
  • Sarcoidosis (formation of granulomas or clusters of immune cells)
  • Hashimoto's disease (when one's immune system attacks the thyroid gland)
  • Wegener's granulomatosis (inflammation of the blood vessels)
  • Stress or anxiety

Neurological Conditions

Those suffering from neurological conditions like autonomic dysreflexia (disorderly reflexes), post traumatic syringomyelia (a fluid-filled cyst in the spinal cord), stroke and dysautonomia (due to autonomic neuropathy or damage to the nervous system) are prone to night sweats. 
Medications to control these conditions may also cause night sweats. Cerebral palsy, epilepsy, cerebral and brain stem strokes, spinal cord infarction, chronic paroxysmal hemicrania (sudden onset of migraine), or any trauma or injury to the head can also be plausible reasons.

Sleep Apnea

If daytime sleepiness and excessive snoring is observed along with sweating, you should get yourself examined for sleep apnea. Such sweating is also accompanied by heartburn, excessive urge to urinate at night, sunken chest (in children) during sleep and dry mouth in the morning.
In severe cases, this condition could cause memory impairment, arrhythmia, impotence, rapid weight gain or heart disease. Check for disturbances in rapid eye movement sleep as well. Obstructive Sleep Apnea Syndrome can result in death, and therefore, medical help must be sought if such symptoms are experienced.
Phentermine, which is a drug that is prescribed for controlling obesity, is also known to cause night sweats in people suffering from sleep apnea. Polysomnography tests are usually carried out to diagnose sleep related breathing disorders (SRBDs).
Quinizarin powder, which turns purple on contact with sweat, is applied to the affected areas to test for excessive perspiration.

Medication

Medicines that may have night sweats as one of their side effects may include:
  • Antidepressants
  • Antipyretics
  • Antihypertensives
  • Antihistamines
  • Antipsychotics
  • Hypoglycemic agents
  • Hormone therapy drugs
  • Cortisone medications (prednisone and prednisolone)
  • Medicines taken to lower fever such as aspirin and acetaminophen
  • Medicines containing nitroglycerin, niacin, tamoxifen, phenothiazine, hydrazine, etc.
Some other drugs you need to be careful with:
  • Accupril
  • Accutane
  • Altace
  • Ambien
  • Amnesteem
  • Anzemet
  • Arava
  • Aricept
  • Aromasin
  • Avinza
  • Bextra
  • Black Cohosh
  • Biaxin-xl
  • Celexa
  • Cozaar
  • Cymbalta
  • Dilaudid
  • Diovan
  • Eligard
  • Evoxac
  • Fortovase
  • Oxycontin
  • Viagra
  • Zoloft

Menopause or Andropause

In women, perimenopause or menopause is the most common cause of night sweats and hot flashes. Some males also suffer from night sweats if they go through the male version of menopause, called andropause (around 5% of the male population is affected by it). 
It causes a gradual decrease in testosterone levels, and can lead to many other changes in the body and mental state.

Hormonal Disorders/Changes

Those suffering from hormonal disorders such as pheochromocytoma (a neuroendocrine tumor), carcinoid syndrome (occurring secondary to neuroendocrine tumors) or hyperthyroidism are prone to flushes and night sweats.
In hypoglycemia (especially nocturnal hypoglycemia), people need to take insulin to control glucose levels in the body. This can also cause night sweats. PMS (premenstrual syndrome) and pregnancy can cause hormonal changes, thereby making women prone to sweating in bed.
Medication taken for nausea during pregnancy can also lead to sweating. Ovarian failure and diabetes mellitus (nocturnal hypoglycemia) are other common causes.

Rheumatological Causes

Certain types of arthritis like Takayasu's arteritis, temporal arteritis, etc., also trigger the condition.

Malignancies/Cancers

Lymphoma (tumor of lymphoid cells) and leukemia of various types like:
  • Non-Hodgkin's lymphoma
  • Hodgkin's lymphoma
  • Acute myelogenous leukemia
  • Human T-cell leukemia
  • Chronic myelogenous leukemia
  • Acute lymphoblastic leukemia
  • Hairy cell leukemia
  • Chronic lymphocytic leukemia
Other types of malignancies like breast cancer can lead to this condition.

Post Surgery/Medical Procedures

Chemotherapy or orchiectomy (removal of the testicles), which is performed on patients with prostate cancer is known to cause heavy perspiration in some patients.

Substance Abuse

Excessive consumption of alcohol and substance abuse could be a contributory factor for sleep hyperhidrosis. Some of the commonly abused drugs include heroin, marijuana and certain prescription drugs. Also, abnormal sweating could even be a withdrawal symptom.

Mercury Poisoning

Exposure to mercury may cause severe problems, one of which is hyperhidrosis. It is often accompanied by ataxia and several other gastrointestinal, cardiovascular and neurological conditions. The immune system is also adversely affected, leaving the body prone to infections.

Severity of Night Sweats

In mild sweating, one does not need to change his or her clothing. Removing the blankets or ventilating the room will alleviate the discomfort. In moderate to slightly severe forms, there is heavy sweating on the face or some other parts of the body. So, one has to wake up to wipe or wash the affected areas.
In extremely severe cases, a patient may require to change his/her clothing or take a bath due to excessive drenching. Sweating too much causes one to lose sleep, as one has to wake up frequently to wash up. In some patients, this can even be a lifelong condition.

Women and Night Sweats

  • 8 out of 10 menopausal women experience night sweats.
  • Young African-American women are more prone to night sweats than their Hispanic and Caucasian counterparts.
  • Women, with excess body fat; those consuming caffeine, alcohol, etc.; those who follow a diet rich in processed food and sugars; and those not following a balanced diet are more susceptible to night sweats.
  • Approximately 15 percent of women require medication to treat problems related to night sweats.

Differentiate Night Sweats from Normal Sweating

The longer you have had night sweats, the less likely they are due to a temporary infection. So, first figure out how long you have had them. If your body temperature is normal at say 5 - 6 p.m. in the evening, but rises during the night and is accompanied by sweating, you should seek medical help so as to identify the exact cause.
An X-ray of the chest or even a CT scan can be done to detect tuberculosis or any other infections or abnormalities in the thoracic region. Similar scans of the abdomen may be performed to detect abscess or malignant growth. Blood tests can also reveal the nature of the infection.
There are many other tests that may be needed to make the correct diagnosis. Looking for other signs specific to the disease will result in faster diagnosis.

Treatment Options

The treatment depends upon the underlying cause. At times, symptomatic treatment may be considered. The available options are:
  • Use of antiperspirants containing aluminum chloride hexahydrate as the main ingredient may prove beneficial.
  • Iontophoresis, which involves the delivery of certain drugs or chemicals into the skin by passing a small electric current through the skin, can be used to treat excessive sweating. It is effective in reducing sweating in certain parts of the body.
  • Use of a class of drugs known as anticholinergics may be suggested.
  • Use of Botulinum neurotoxin (Botox) could be suggested.
  • Endoscopic Thoracic Sympathectomy (ETS), a controversial surgical procedure is mentioned as a last resort for excessive sweating. Compensatory sweating is one of the common adverse effects of this surgery.
Night sweats may not be a cause of serious concern always, but in some cases, you need to find out their underlying cause early enough so as to avoid any complications that may arise later.
Disclaimer: This story is for informative purposes only, and should not be used as a replacement for expert medical advice.