Sweating helps the body stay cool. In most cases, it is perfectly natural. People sweat more in warm temperatures, when they exercise, or in response to situations that make them nervous, angry, embarrassed, or afraid.

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Excessive sweating occurs without such triggers. People with hyperhidrosis appear to have overactive sweat glands. The uncontrollable sweating can lead to significant discomfort, both physical and emotional.

When excessive sweating affects the hands, feet, and armpits, it is called focal hyperhidrosis. In most cases, no cause can be found. It seems to run in families.

Sweating that is not caused by another disease is called primary hyperhidrosis.

If the sweating occurs as a result of another medical condition, it is called secondary hyperhidrosis. The sweating may be all over the body (generalized) or it may be in one area (focal). Conditions that cause secondary hyperhidrosis include:

• Acromegaly
• Anxiety conditions
• Cancer
• Carcinoid syndrome
• Certain medicines and substances of abuse
• Glucose control disorders (diabetes and hypoglycemia)
• Heart disease, such as heart attack
• Overactive thyroid
• Lung disease
• Menopause
• Parkinson disease
• Pheochromocytoma (adrenal gland tumor)
• Spinal cord injury
• Stroke
• Tuberculosis or other infections

The primary symptom of hyperhidrosis is sweating.

Visible signs of sweating may be noted during a visit with a health care provider. Tests may also be used to diagnose excessive sweating, including:

• Starch-iodine test -- An iodine solution is applied to the sweaty area. After it dries, starch is sprinkled on the area. The starch-iodine combination turns a dark blue to black color wherever there is excess sweat.
• Paper test -- Special paper is placed on the affected area to absorb the sweat and then weighed. The heavier it weighs, the more sweat has accumulated.
• Blood tests -- These may be ordered if thyroid problems or other medical conditions are suspected.
• Imaging tests may be ordered if a tumor is suspected.

You may also be asked details about your sweating, such as:

• Location -- Does it occur on your face, palms, or armpits, or all over the body?
• Time pattern -- Does it occur at night? Did it begin suddenly?
• Triggers -- Does the sweating occur when you are reminded of something that upsets you (such as a traumatic event)?
• Other symptoms -- Weight loss, pounding heartbeat, cold or clammy hands, fever, lack of appetite.

A wide range of common treatments for hyperhidrosis includes:

• Antiperspirants -- Excessive sweating may be controlled with strong antiperspirants, which plug the sweat ducts. Products containing 10% to 20% aluminum chloride hexahydrate are the first line of treatment for underarm sweating. Some people may be prescribed a product containing a higher dose of aluminum chloride, which is applied nightly onto the affected areas. Antiperspirants can cause skin irritation, and large doses of aluminum chloride can damage clothing. Note: Deodorants do not prevent sweating but are helpful in reducing body odor.
• Medicines -- Use of some medicines may prevent stimulation of sweat glands. These are prescribed for certain types of hyperhidrosis such as excessive sweating of the face. Medicines can have side effects and are not right for everyone.
• Iontophoresis -- This procedure uses electricity to temporarily turn off the sweat gland. It is most effective for sweating of the hands and feet. The hands or feet are placed into water, and then a gentle current of electricity is passed through it. The electricity is gradually increased until the person feels a light tingling sensation. The therapy lasts about 10 to 30 minutes and requires several sessions. Side effects, although rare, include skin cracking and blisters.
• Botulinum toxin -- Botulinum toxin is used to treat severe underarm, palmar (hand), and plantar (foot) sweating. This condition is called primary axillary hyperhidrosis. Botulinum toxin injected into the underarm temporarily blocks the nerves that stimulate sweating. Side effects include injection-site pain and flu-like symptoms. Botulinum toxin used for sweating of the palms can cause mild, but temporary weakness and intense pain.
• Endoscopic thoracic sympathectomy (ETS) -- In severe cases, a minimally invasive surgical procedure called sympathectomy may be recommended when other treatments do not work. The procedure cuts a nerve, turning off the signal that tells the body to sweat excessively. It is usually done on people whose palms sweat much more heavily than normal. It may also be used to treat extreme sweating of the face. ETS does not work as well for those with excessive armpit sweating.
• Underarm surgery -- This is surgery to remove the sweat glands in the armpits. Methods used include laser, curettage (scraping), excision (cutting), or liposuction. These procedures are done using local anesthesia.

With treatment, hyperhidrosis can be managed. Your provider can discuss treatment options with you.

Contact your provider if you have sweating:

• That is prolonged, excessive, and unexplained.
• With or followed by chest pain or pressure.
• With weight loss.
• That occurs mostly during sleep.
• With fever, weight loss, chest pain, shortness of breath, or a rapid, pounding heartbeat. These symptoms may be a sign of an underlying disease, such as overactive thyroid.

Sweating - excessive; Perspiration - excessive; Diaphoresis

Farrugia ME, Kavanagh GM. Hyperhidrosis. In: Lebwohl MG, Heymann WR, Coulson IH, Murrell DF, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 6th ed. Philadelphia, PA: Elsevier; 2022:chap 109.

James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM. Diseases of the skin appendages. In: James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 13th ed. Philadelphia, PA: Elsevier; 2020:chap 33.

Miller JL. Diseases of the eccrine and apocrine sweat glands. In: Bolognia JL, Schaffer JV, Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2018:chap 39.

Updated by: Elika Hoss, MD, Assistant Professor of Dermatology, Mayo Clinic, Scottsdale, AZ. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.