Autonomic Testing
Reviewed
Autonomic testing helps find out if your autonomic nervous system (ANS) is working as well as it should. The ANS controls body functions that happen automatically, such as breathing, heartbeat, body temperature, and digestion. If there are problems with the ANS, it is known as autonomic neuropathy. Autonomic testing can show which part of your ANS is affected and how seriously it's affected.
Preparation and collection
Follow your provider's specific instructions. Common preparations: avoid caffeine for 8 hours, stay well hydrated with noncaffeinated beverages the day before, avoid alcohol for 12 hours, and do not smoke or use tobacco for 4 hours before the test. Your provider may also ask you to stop certain medications.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- Physical risks: fainting, nausea, vomiting, weakness during tilt table test; skin irritation from electrodes in sweat tests.
- Emotional risks: possible anxiety during testing or from fainting episode.
- False positives/negatives: not explicitly stated, but results are interpreted in context of history and exam; abnormal results do not alone diagnose a condition.
- No specimen collection; no laboratory analysis involved.
What to do next
Your healthcare provider will consider your medical history, symptoms, and physical exam alongside your test results. If results are abnormal, additional tests may be ordered to determine the cause of the autonomic nervous system problem.