Sweating is the release of liquid from the body's sweat glands. This liquid contains salt. This process is also called perspiration.
Sweating helps your body stay cool. Sweat is commonly found under the arms, on the feet, and on the palms of the hands.
The amount you sweat depends on how many sweat glands you have.
A person is born with about 2 to 4 million sweat glands, which begin to become fully active during puberty. Men's sweat glands tend to be more active.
Sweating is controlled by the autonomic nervous system. This is the part of the nervous system that is not under your control. Sweating is the body's natural way of regulating temperature.
Things that can make you sweat more include:
Hot weather
Exercise
Situations that make you nervous, angry, embarrassed, or afraid
Heavy sweating may also be a symptom of
(also called a hot flash).
Causes may include:
Alcohol
Caffeine
Cancer
Complex regional pain syndrome
Emotional or stressful situations (anxiety)
Essential
Exercise
Fever
Infection
Low blood sugar (hypoglycemia)
Medicines, such as thyroid hormone, morphine, medicines to reduce fever, and medicines to treat mental disorders
Menopause
Spicy foods (known as gustatory sweating)
Warm temperatures
Withdrawal from alcohol, sedatives, or narcotic painkillers
After sweating a lot, you should:
Drink plenty of fluids (water, or fluids containing electrolytes such as sports drinks) to replace sweat.
Lower room temperature a little bit to prevent more sweating.
Wash your face and body if the salt from sweat has dried on your skin.
Contact your health care provider if sweating occurs with:
Chest pain
Fever
Rapid, pounding heartbeat
Shortness of breath
Weight loss
These symptoms may indicate a problem, such as
or an infection.
Also contact your provider if:
You sweat a lot or sweating lasts for a long time or cannot be explained
Sweating occurs with or is followed by
or pressure
You lose weight from sweating or often sweat during sleep
Perspiration
Chelimsky T, Chelimsky G. Disorders of the autonomic nervous system. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 107.
Hall JE, Hall ME. Body temperature regulation and fever. In: Hall JE, Hall ME, eds. Guyton and Hall Textbook of Medical Physiology. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 74.
McGrath JA. The structure and function of skin. In: Calonje E, Brenn T, Lazar AJ, Billings SD, eds. McKee's Pathology of the Skin. 5th ed. Philadelphia, PA: Elsevier; 2020:chap 1.
Updated by: Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.