Diagnosis

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 a 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.