Preparing for vascular and autonomic testing

How to prepare for Measura testing

To prepare for Measura testing, avoid alcohol for 24 hours, skip caffeine and nicotine that morning, fast overnight if asked, drink water, wear loose clothing and bring a complete medication list. Do not stop any medication unless told to.

Preparation matters more than usual here, because several of these assessments measure physiology that food, caffeine, nicotine and medication move around.

What should I avoid the day before testing?

• Avoid alcohol for 24 hours. It changes heart rate variability measurably.
• Keep to your usual sleep. A short night lowers the same measurements a disease would.
• Do not do unusually heavy exercise. Vigorous training shifts autonomic readings for a day or more.

Can I eat, drink coffee or smoke the morning of the test?

• Fast if you have been asked to. Metabolic rate measurement and most laboratory panels require an overnight fast — water is fine and encouraged.
• No caffeine. Coffee, tea, energy drinks and pre-workout supplements all alter heart rate variability and vascular tone for hours.
• No nicotine. Smoking or vaping shortly before a vascular study constricts the vessels you are trying to measure.
• Drink water. Dehydration lowers blood pressure on standing and can make an autonomic result look worse than it is.

What should I wear to the test?

Loose clothing with sleeves that push above the elbow and pants that roll above the knee. Cuffs go directly on the skin of both arms and both ankles. Bring socks you do not mind removing — the sudomotor plates and the toe sensor need bare feet.

Should I stop my medications before testing?

Do not stop anything without being told to. Bring a complete list instead, including doses and timing. Several common medications change these measurements, and the person reading the report needs to know which ones you are on rather than have you guess.

Classes that matter most: beta-blockers and other blood pressure medications, diuretics, anticholinergics, antidepressants, medications for overactive bladder, and anything that causes dry mouth. Supplements count too.

What should I bring to my appointment?

• Photo identification and your insurance card.
• The medication and supplement list.
• Recent laboratory results if you have them, especially glucose, HbA1c and lipids.
• Your glasses and hearing aids — both are needed for cognitive and balance testing.
• The name and address of the clinician who should receive the report.

If you use a pacemaker, an implanted defibrillator or another implanted electrical device, tell us when you book. If you are pregnant, tell us as well — several assessments are adjusted.

Common questions

Can I take my blood pressure medication that morning?

Ask when you book rather than deciding on your own, and never skip a dose unprompted. What happens before your appointment.

What if I forget and drink coffee?

Tell us. Some assessments can be rescheduled within the same visit; others are simply annotated so the reading is interpreted correctly. Why context changes a result.

Do I have to fast for the whole assessment?

Only for metabolic rate measurement and laboratory work. Those are scheduled first so you can eat afterwards. Why measured metabolic rate needs a fast.

What should you not do before an ABI test?

Do not drink alcohol for 24 hours before the test, and do not have coffee, tea, energy drinks, pre-workout supplements, cigarettes or vapes that morning. Skip unusually heavy exercise the day before and keep to your usual sleep. Do not stop any medication on your own. Bring a complete list instead, because each of these things changes the vessels and nerves being measured.

What should I expect during autonomic testing?

Expect cuffs placed directly on the skin of both arms and both ankles, so wear sleeves that push above the elbow and pants that roll above the knee. Your socks come off, because the sudomotor plates and the toe sensor need bare feet. Balance and cognitive testing can be part of the same visit, so bring your glasses and hearing aids.

Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP, medical director of Measura. Last reviewed August 20, 2026.