by EBSCO Medical Review Board


The Quantitative Sudomotor Axon Reflex Test (QSART) measures how well the nerves that control sweating are working.

Reasons for Procedure

QSART may be done to diagnose or assess:

Possible Complications

Problems from the test are rare.

What to Expect

Prior to Test

  • Do not eat or drink anything with caffeine or smoke 4 hours before the test.
  • Do not drink anything with alcohol for 12 to 14 hours before the test.
  • Talk to your doctor if you take any medicines, herbs, or supplements.

Certain medicines may interfere with the test. These medicines may need to be stopped up to 1 week before the procedure. Talk to your doctor before the procedure about all medicines you are taking.


Anesthesia will not be needed. The test does not cause pain, just a mild burning or discomfort.

Description of the Procedure

The skin on the leg and wrist will be cleaned. Three electrodes filled with a chemical will be placed on the leg and 1 electrode will be placed on the wrist. A mild electrical current will be used to help the chemical stimulate the sweat glands. The sweat response is measured.

How Long Will It Take?

2 to 3 hours

Will It Hurt?

A mild burning sensation may be felt at the electrode during the test.

Post-procedure Care

At the Care Center

Right after the procedure, the electrodes will be removed and your skin will be cleaned. You can leave after the procedure.

It may take a few days to receive the test results.

Problems To Look Out For

Call your doctor if you have a rash at the electrode site.

If you think you have an emergency, call for medical help right away.


UPMC Department of Neurology 

The Foundation for Peripheral Neuropathy 


Health Canada 

The Hereditary Neuropathy Foundation of Canada 


Autonomic disorders program. Stanford Health Care website. Available at: Accessed April 14, 2022.

Automatic neuropathy. EBSCO DynaMed website. Available at: Accessed April 14, 2022.

Diagnosing nerve disorders. Oregon Health and Science University Brain Institute website. Available at: Accessed April 14, 2022.

Peripheral neuropathy fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: Accessed April 14, 2022

Quantitative sudomotor axon reflex test (QSART). Cleveland Clinic website. Available at: Accessed April 14, 2022.

Revision Information

  • Reviewer: EBSCO Medical Review Board Dr. Lukas Rimas, MD
  • Review Date: 03/2022
  • Update Date: 04/14/2022