Your doctor is likely to suspect anhidrosis based on your signs and symptoms, your medical history, and a physical exam. But you may need certain tests to confirm the diagnosis. These include:

  • Sweat test. During this test, known as thermoregulatory sweat test, you're coated with a powder that changes color when and where you sweat. You then enter a chamber that causes your body temperature to increase to a level that makes most people perspire. Digital photos document the results, and the whole body surface can be tested at once.
  • Skin biopsy. In some cases, your doctor might request a biopsy of the area suspected of anhidrosis. For this test, skin cells and sometimes sweat glands are removed for examination under a microscope.


Anhidrosis that affects a small part of your body usually isn't a problem and doesn't need treatment. But large areas of decreased perspiration can be life-threatening. Treatments may depend on the condition that's causing the anhidrosis.

Treating heat-related problems

Overheating needs prompt treatment to prevent symptoms from becoming worse.

Heat cramps

To relieve cramping:

  • Rest and cool down
  • Drink cool fruit juice or a sports drink that contains electrolytes
  • Get medical care if cramps become worse or don't go away in about an hour
  • Wait at least several hours before returning to strenuous activity

Heat exhaustion

Act quickly when someone develops signs and symptoms of heat exhaustion, such as nausea, dizziness and a rapid heartbeat:

  • Move the person into a shady or air-conditioned space, and elevate his or her legs slightly.
  • Loosen the person's clothing, and remove any heavy pieces of clothing.
  • Have the person drink a cool beverage that doesn't have caffeine or alcohol.
  • Spray or sponge the person with cool water.
  • If symptoms don't improve quickly, call 911 or emergency medical help.


Heatstroke requires immediate medical care, so call 911 or emergency medical help. This condition can be fatal if left untreated. Until help arrives:

  • Move the person into a shady or air-conditioned space.
  • Spray or sponge the person with cool water. Or wrap him or her in wet towels or sheets. Use a fan or newspaper to increase air circulation.
  • Have the person drink a cool beverage that doesn't have caffeine or alcohol if he or she is able.

Preparing for your appointment

You're likely to start by seeing your family doctor or a general practitioner. You may then be referred to a doctor who specializes in skin disorders (dermatologist).

Here's information to help you get ready for your appointment.

What you can do

  • Be aware of pre-appointment restrictions. When you make the appointment, ask if you need to do anything to prepare, such as modifying your diet.
  • Write down your symptoms, including ones that seem unrelated to your reason for scheduling an appointment.
  • Write down key personal information, including major stresses or recent life changes.
  • List all medications, vitamins and supplements you take.
  • Ask a family member or friend to come with you to help you remember information you're given.
  • Write down questions to ask your doctor.

Preparing a list of questions can help you make the most of your time with your doctor. For anhidrosis, some basic questions to ask your doctor include:

  • Why don't certain parts of my body sweat?
  • What tests do I need?
  • What caused this condition?
  • Will I always have this condition?
  • What treatments are available, and which do you recommend?
  • How can I best manage this condition with my other health conditions?
  • Should I restrict activities?
  • Do you have any brochures or other printed material for me? What websites do you recommend?

Don't hesitate to ask other questions, as well.

What to expect from your doctor

Your doctor is likely to ask you a number of questions, including:

  • When did you notice you weren't sweating?
  • What parts of your body don't perspire?
  • Are you aware of others in your family with similar symptoms?
  • Do you have other symptoms?
  • Does anything seem to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?
  • Did symptoms begin when you changed a medication or were diagnosed with another illness?
Dec. 13, 2014
  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.