Sweating is the release of a salty liquid from the body's sweat glands. This process is also called perspiration.
Sweating is an essential function that helps your body stay cool. Sweat is commonly found under the arms, on the feet, and on the palms of the hands.
How much you sweat depends on how many sweat glands you have. A person is born with about two to four million sweat glands. The glands start to become fully active during puberty. Women have more sweat glands then men, but men's glands are more active.
Sweating is controlled by the autonomic nervous system, the part of the nervous system that is not under your control. Because sweating is the body's natural way of regulating temperature, people sweat more when it's hot outside. People also sweat more when they exercise, or in response to situations that make them nervous, angry, embarrassed, or afraid.
Excessive sweating may also be a symptom of menopause.
- Complex regional pain syndrome
- Emotional or stressful situations (anxiety)
- Essential hyperhidrosis
- Fever and infections
- Low blood sugar (hypoglycemia)
- Medications such as thyroid hormone, morphine, drugs to reduce fever, and medicines to treat mental disorders
- Spicy foods (known as "gustatory sweating")
- Warm temperatures
- Withdrawal from alcohol or narcotic painkillers
After sweating, you should:
- Drink plenty of water to replace lost body fluids
- Slightly lower room temperature to prevent more sweating
- Wash your face and body if the salt from sweat has dried on your skin
When to Contact a Medical Professional
Contact your health care provider if sweating occurs with:
- Chest pain
- Rapid, pounding heartbeat
- Shortness of breath
- Weight loss
These symptoms may indicate a problem, such as hyperthyroidism or infection.
Also call your health care provider if:
- You sweat a lot or sweating lasts for a long time or can't be explained
- Sweating occurs with or is followed by chest pain or pressure
- You also lose weight or usually sweat during sleep
Robertson D. Disorders of the autonomic nervous system. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth Heinemann Elsevier; 2008:chap 81.
Saper CB. Autonomic disorders and their management. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 445.
Review Date: 5/29/2011
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.