Overview

Anhidrosis is the inability to sweat normally. When you don't sweat (perspire), your body can't cool itself, which can lead to overheating and sometimes to heatstroke — a potentially fatal condition.

Anhidrosis — sometimes called hypohidrosis — can be difficult to diagnose. Mild anhidrosis often goes unrecognized. Dozens of factors can cause the condition, including skin trauma and certain diseases and medications. You can inherit anhidrosis or develop it later in life.

Treatment of anhidrosis involves addressing the underlying cause, if one can be found.

Symptoms

Signs and symptoms of anhidrosis include:

  • Little or no perspiration
  • Dizziness
  • Muscle cramps or weakness
  • Flushing
  • Feeling hot

A lack of perspiration can occur:

  • Over most of your body (generalized)
  • In a single area
  • In scattered patches

Areas that can sweat may try to produce more perspiration, so it's possible to sweat profusely on one part of your body and very little or not at all on another. Anhidrosis that affects a large portion of your body prevents proper cooling, so vigorous exercise, hard physical work and hot weather can cause heat cramps, heat exhaustion or even heatstroke.

Anhidrosis can develop on its own or as one of several signs and symptoms of another condition, such as diabetes or skin injury.

When to see a doctor

If you barely sweat, even when it's hot or you're working or exercising strenuously, talk to your doctor. Talk to your doctor if you notice you're sweating less than usual. Because anhidrosis increases your risk of heatstroke, seek medical care if you develop signs or symptoms of a heat-related illness, such as:

  • Weakness
  • Nausea
  • Dizziness
  • Rapid heartbeat
  • Goose bumps on the skin, despite warm temperatures

Causes

Anhidrosis occurs when your sweat glands don't function properly, either as a result of a condition you're born with (congenital condition) or one that affects your nerves or skin. Dehydration also can cause anhidrosis. Sometimes the cause of anhidrosis can't be found.

Causes of anhidrosis include:

  • Conditions you're born with, such as certain congenital displasias that affect the development of sweat glands
  • Inherited conditions that affect your metabolic system, such as Fabry's disease
  • Connective tissue diseases, such as Sjogren's syndrome, which causes dry eyes and mouth
  • Skin damage, such as from burns or radiation therapy, or diseases that clog your pores (poral occlusion), such as psoriasis
  • Conditions that cause nerve damage (neuropathy), such as diabetes, alcoholism and Guillain-Barre syndrome
  • Certain drugs, such as morphine and botulinum toxin type A, and those used to treat psychosis.

Risk factors

Certain factors make anhidrosis more likely, including:

  • Age. People age 65 and older, infants, and children are more prone to heat stress, which can contribute to anhidrosis.
  • Certain health problems. Any medical condition that damages your autonomic nerves, such as diabetes, makes sweat gland problems more likely.
  • Skin disorders. Many diseases that irritate or inflame the skin also affect the sweat glands. They include psoriasis; exfoliative dermatitis, which is marked by severe skin scaling; heat rash; scleroderma, which causes hard, tight skin; and ichthyosis — extremely dry, scaly skin.
  • Genetic abnormalities. Mutations in certain genes can lead to disorders that affect the sweat glands.

Complications

Heat-related illnesses are the most serious complications of anhidrosis. Children are especially vulnerable because their core temperatures rise faster than adults', and their bodies release heat less efficiently.

Heat-related problems include:

  • Heat cramps. These muscle spasms, which can tighten muscles in your legs, arms, abdomen and back, are generally more painful and prolonged than are typical nighttime leg cramps.
  • Heat exhaustion. Signs and symptoms such as weakness, nausea and a rapid heartbeat usually begin after strenuous exercise. Monitor someone with heat exhaustion because symptoms can quickly become worse.
  • Heatstroke. This life-threatening condition occurs when your body temperature reaches 104 F (40 C) or higher. If not treated immediately, heatstroke can cause hallucinations, loss of consciousness, coma and even death.

Prevention

Anhidrosis often can't be prevented, but serious heat-related illnesses can. To stay safe:

  • Wear loose, light clothing when it's warm.
  • Stay indoors on hot days.
  • Monitor your activity level closely so you don't overdo.
  • Learn the signs of heat-related illness and how to treat them.
Dec. 13, 2014
References
  1. Goldsmith LA, et al., eds. Fitzpatrick's Dermatology in General Medicine. 8th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=740. Accessed Nov. 10, 2014.
  2. Bolognia JL, et al. Dermatology. 3rd ed. Philadelphia, Pa.: Saunders Elsevier; 2012. https://www.clinicalkey.com. Accessed Nov. 10, 2014.
  3. Tay LK, et al. Acquired idiopathic anhidrosis: A diagnosis often missed. Journal of the American Academy of Dermatology. 2014;71:499.
  4. Kliegman RM, et al. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.clinicalkey.com. Accessed Nov. 10, 2014.
  5. Extreme heat prevention guide. Centers for Disease Control and Prevention. http://www.bt.cdc.gov/disasters/extremeheat/heat_guide.asp. Accessed Nov. 10, 2014.