Sweating is your body’s way of cooling itself off. Some people aren’t able to sweat normally because their sweat glands are no longer functioning properly. This condition is known as hypohidrosis, or anhidrosis. It can affect your entire body, a single area, or scattered areas.
The inability to sweat normally can cause overheating. This can lead to heat stroke, which is a potentially life-threatening condition.
Hypohidrosis can be difficult to diagnose. This means that mild hypohidrosis often goes unnoticed. The condition has many causes. It can be inherited at birth or develop later in life.
As you age, it’s normal for your ability to sweat to diminish. Conditions that damage your autonomic nerves, such as diabetes, also make problems with your sweat glands more likely.
Any condition that causes nerve damage can disrupt the functioning of your sweat glands. This includes:
- Ross syndrome, which is a rare disorder characterized by sweating and pupils that don’t dilate properly
- Parkinson’s disease
- multiple system atrophy
- amyloidosis, which occurs when a protein called an amyloid builds up in your organs and affects your nervous system
- Sjogren’s syndrome
- small cell lung cancer
- Fabry disease, which is a genetic disorder that causes fat to build up in your cells
- Horner syndrome, which is a form of nerve damage that occurs in your face and eyes
Skin Damage and Disorders
Skin damage from severe burns can permanently damage your sweat glands. Other possible sources of damage include:
Skin disorders that inflame the skin can also affect your sweat glands. These include:
Taking certain medications, particularly those known as anticholinergics, can result in reduced sweating. These medications have side effects that include a sore throat, dry mouth, and reduction in perspiration.
Some people may inherit a damaged gene that causes their sweat glands to malfunction. An inherited condition called “hypohidrotic ectodermal dysplasia” causes people to be born with either very few or no sweat glands.
The symptoms of hypohidrosis include:
- minimal sweating even when other people are sweating heavily
- muscle cramps or weakness
- a flushed appearance
- feeling overly hot
Mild hypohidrosis may go unnoticed unless you engage in vigorous exercise and become overheated because you’re not sweating normally.
Your doctor will need to take a thorough medical history to diagnose this condition. You should share all symptoms that you’ve experienced with your doctor. This includes breaking out in a red rash or skin flushing when you should be sweating. It’s important to tell them if you sweat in some parts of your body but not in others.
Your doctor may use any of the following tests to confirm a diagnosis of hypohidrosis:
- During the axon reflex test, small electrodes are being used to stimulate your sweat glands. The volume of sweat produced is measured.
- The silastic sweat imprint test measures where you sweat.
- During the thermoregulatory sweat test, your body is coated with a powder that changes color in areas where you sweat. You enter a chamber that causes your body temperature to reach a level at which most people would sweat.
- During a skin biopsy, some skin cells and perhaps some sweat glands are removed and examined under a microscope.
Hypohidrosis that affects only a small part of your body usually won’t cause problems and may not require treatment. If an underlying medical condition is causing hypohidrosis, your doctor will treat that condition. This may help reduce your symptoms.
If medications are causing your hypohidrosis, your doctor may recommend trying another medication or reducing your dosage. While this isn’t always possible, adjusting medications may help to improve sweating.
It may not be possible to prevent hypohidrosis, but you can take steps to avoid serious illnesses related to overheating. Wear loose clothing that’s in light colors, and don’t overdress when it’s hot. Stay inside if possible, and take care not to overexert yourself when it’s hot.
You can also take steps to cool your body off and avoid overheating. This includes applying water or cool cloths to your skin to make you feel like you're sweating. When the water evaporates, you’ll feel cooler.
If it’s left untreated, hypohidrosis can cause your body to overheat. Overheating requires quick treatment to prevent it from worsening into heat exhaustion or heat stroke. Heat stroke is a life-threatening condition. You should call 911 or visit an emergency room if you’re having a heat stroke.