Hyperhidrosis: Causes

Hyperhidrosis is a treatable medical condition that makes people sweat excessively. They sweat more than is needed to cool their body.

What causes excessive sweating?

The cause depends on the type of hyperhidrosis you have. There are two types of hyperhidrosis:

• Primary hyperhidrosis

• Secondary hyperhidrosis

Most people have a type of excessive sweating called primary hyperhidrosis. It’s also called primary focal hyperhidrosis or focal hyperhidrosis. Focal means limited to a specific area. With this type of hyperhidrosis, excessive sweating occurs in one or two areas of the body like the underarms, palms, soles, or head.

Most people who have this type of hyperhidrosis are otherwise healthy.

It’s believed that this type of excessive sweating is caused by faulty signals coming from certain nerves, which tell the body when to sweat. It’s possible that these nerves over-react, which leads to excessive sweating.

A patient is diagnosed with primary hyperhidrosis when:

• Excessive sweating lasts for more than 6 months.

• Two or more of the following occur:

  • Excessive sweating happens more than once a week.

  • You’re 24 years of age or younger.

  • One or more blood relatives have/had excessive sweating.

  • Sweating occurs in one or two areas. For example, one area could be your underarms. Two areas might be your underarms and palms.

  • Sweating affects your everyday activities, such as the ability to use a computer or give presentations.

  • Sweating stops while you’re asleep.

The other type of hyperhidrosis is called secondary hyperhidrosis.

If you’ve been diagnosed with secondary hyperhidrosis, the excessive sweating is usually due to one of the following:

• A medication you’re taking

• Another medical condition you have

Medications that can cause secondary hyperhidrosis include some antibiotics, antivirals, insulin, and antidepressants. Keep in mind that not every medication in a class like antivirals has excessive sweating as a possible side effect.

Your dermatologist or the doctor who prescribed the medication can tell you if excessive sweating is a possible side effect.

Suddenly stopping a medication can cause side effects

If you think a medication could be causing your hyperhidrosis, talk with the doctor who prescribed the medication. Until you can talk with the doctor, continue taking the medication.

Secondary hyperhidrosis can also be caused by withdrawing from an addictive drug like alcohol, cocaine, or heroin.

Medical conditions that can cause hyperhidrosis include diabetes, Parkinson’s disease, and rheumatoid arthritis. Heart failure and stroke can also cause secondary hyperhidrosis, as can menopause.

Hyperhidrosis is common among people who have Parkinson’s disease

Parkinson’s can affect the part of the nervous system that controls sweating. Excessive sweating can worsen as Parkinson’s progresses. You may also sweat excessively when medication that you’re taking to control Parkinson's wears off.

Unlike primary hyperhidrosis, secondary hyperhidrosis can cause you to sweat while you’re asleep.

Who is most likely to develop hyperhidrosis?

Anyone can develop this treatable medical condition. However, some people are more likely to develop it.

You’re more likely to develop primary hyperhidrosis if you:

• Have one or more blood relative(s) who have/had excessive sweating.

• Are 24 years of age or younger.

You may develop secondary hyperhidrosis if you have one of the following:

• Take medication (described above) that can cause excessive sweating.

• Have a medical condition (described above) that can lead to excessive sweating.

• Experience withdrawal symptoms from an addictive drug like alcohol, cocaine, or heroin.

Getting an early diagnosis and the right treatment can reduce sweating, helping you feel more comfortable. To find out how dermatologists diagnose this condition and create an individualized treatment plan, go to: Hyperhidrosis: Diagnosis and treatment.

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References
Kurta A, Glaser DA. “Hyperhidrosis and anhidrosis.” In: Kang S, Amagai M, et al. Fitzpatrick’s Dermatology (ninth edition). McGraw Hill Education, New York, 2019: 1459-63.

Lin J, Ou R, et al. “Hyperhidrosis in Parkinson's disease: A 3-year prospective cohort study.” J Eur Acad Dermatol Venereol. 2022 Jul;36(7):1104-12.

Miller JL. “Diseases of the eccrine and apocrine sweat glands.” In: Bolognia JL, et al. Dermatology. (fourth edition). Mosby Elsevier, China, 2018:633-6.

Nawrocki S, Cha J.

• “Botulinum toxin: Pharmacology and injectable administration for the treatment of primary hyperhidrosis.” J Am Acad Dermatol. 2020 Apr;82(4):969-79.

• “The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Etiology and clinical work-up.” J Am Acad Dermatol. 2019 Sep;81(3):657-66.

Walling HW. “Clinical differentiation of primary from secondary hyperhidrosis.” J Am Acad Dermatol. 2011 Apr;64(4):690-5.

Written by:
Paula Ludmann, MS

Reviewed by:
Elizabeth Damstetter, MD, FAAD
Neelam Khan, MD, FAAD
William Warren Kwan, MD, FAAD
Temitayo A. Ogunleye, MD, FAAD
Sanna Ronkainen, MD, FAAD

Last updated: 7/16/24