Orthostatic hypotension is diagnosed when your blood pressure drops by at least 20 mmHg systolic (top number) or 10 mmHg diastolic (bottom number) within minutes of standing up. The core diagnostic test is straightforward: your blood pressure is measured while lying down and again after standing, and the difference between those readings determines the diagnosis.
The Active Stand Test
The standard method for diagnosing orthostatic hypotension is called an active stand test, and it can be done in any clinic with a blood pressure cuff. The CDC recommends the following protocol: you lie down for five minutes while your blood pressure and pulse are recorded. Then you stand up, and your blood pressure and pulse are measured again at one minute and three minutes after standing.
The clinician also notes any symptoms you experience during the test, such as dizziness, lightheadedness, blurred vision, or feeling faint. Symptoms that line up with a measurable blood pressure drop strengthen the diagnosis. Some people meet the blood pressure criteria but feel fine, while others feel terrible with smaller drops. Both the numbers and how you feel matter for deciding on treatment.
If your blood pressure drops meet the threshold at the one-minute or three-minute mark, you have what’s called “classic” orthostatic hypotension. If the drop happens only after three minutes of standing, it’s classified as “delayed” orthostatic hypotension. There’s also an “initial” type where blood pressure plunges briefly in the first 15 seconds but recovers quickly. Each subtype suggests different underlying mechanisms and can guide what happens next.
Tilt Table Testing
When a standard stand test doesn’t capture what’s happening, or when fainting episodes need further evaluation, a tilt table test offers a more controlled approach. You lie strapped to a motorized table, and the table is tilted upward to simulate standing without requiring you to use your leg muscles. This isolates the cardiovascular response from the physical effort of getting up.
European guidelines recommend a tilt angle of 60 to 70 degrees with a passive phase lasting 20 to 45 minutes. American guidelines from the ACC, AHA, and HRS recommend 70 degrees for 30 to 40 minutes. Throughout the test, blood pressure and heart rate are continuously monitored. The test is stopped early if you faint. Tilt table testing is particularly useful for detecting delayed orthostatic hypotension that a three-minute stand test might miss, and for evaluating people who can’t safely stand on their own.
Distinguishing Neurogenic From Non-Neurogenic Causes
Not all orthostatic hypotension has the same cause, and one of the most important diagnostic questions is whether the problem originates in the nervous system. Neurogenic orthostatic hypotension (caused by nerve damage affecting blood vessel control) behaves differently from non-neurogenic causes like dehydration, blood loss, or medication side effects.
The key clue is your heart rate response. When blood pressure drops on standing, a healthy nervous system compensates by speeding up the heart. In non-neurogenic orthostatic hypotension, the heart rate typically increases by about 25 beats per minute. In neurogenic cases, the heart averages only about 8 beats per minute of increase, because the nerves responsible for that compensation are damaged.
Researchers at Vanderbilt University found that dividing the change in heart rate by the change in systolic blood pressure gives a reliable diagnostic ratio. A ratio below 0.5 beats per minute per mmHg of blood pressure drop identifies neurogenic orthostatic hypotension with over 90% sensitivity and 88% specificity. This simple calculation can be done from the same measurements taken during a standard stand test, no additional equipment needed.
The Valsalva Maneuver
To get a more detailed picture of how well the autonomic nervous system is functioning, clinicians sometimes use the Valsalva maneuver. You blow into a tube or against resistance for several seconds while blood pressure and heart rate are continuously recorded. This creates a predictable sequence of pressure changes in the chest that the nervous system should respond to in a specific pattern.
In healthy people, blood pressure dips during the strain and then overshoots briefly after release, with corresponding heart rate adjustments. People with autonomic dysfunction show abnormal patterns: the expected blood pressure recovery doesn’t happen, or the heart rate changes are blunted. The specific shape of the response helps clinicians determine whether the sympathetic nervous system (which raises blood pressure), the parasympathetic nervous system (which slows the heart), or both are impaired.
What Symptoms Are Tracked
Diagnosis isn’t purely about numbers. Clinicians also assess how symptoms affect your daily life. The Orthostatic Hypotension Questionnaire (OHQ) is a validated tool with two parts: a six-item symptom scale and a four-item daily activity scale. The symptom scale captures things like dizziness, vision changes, weakness, and fatigue upon standing. The activity scale measures how much these symptoms limit what you can do during the day.
This matters because two people with the same blood pressure drop can have very different experiences. OHQ scores reliably distinguish between severe and less severe cases and are used to track whether treatments are actually helping. If you’re being evaluated for orthostatic hypotension, expect questions not just about dizziness but about how standing affects your ability to do ordinary things like cook, walk to the mailbox, or stand in line at a store.
Checking for Supine Hypertension
One complicating factor that clinicians look for during evaluation is supine hypertension, meaning abnormally high blood pressure while lying down. This is common in people with neurogenic orthostatic hypotension and creates a tricky treatment problem: raising blood pressure to prevent fainting when standing can worsen dangerously high readings when lying flat.
Supine hypertension is generally identified when lying-down blood pressure reaches 160/90 mmHg or higher. Severe cases exceed 180/110 mmHg. This is one reason the diagnostic workup includes that initial five-minute lying-down reading. It’s not just establishing a baseline for the standing test. It’s also screening for a condition that will shape the entire treatment approach. If supine hypertension is present, even simple interventions like sleeping with the head of the bed raised 30 to 45 degrees become part of management.
What You Can Do at Home
If you suspect orthostatic hypotension but haven’t been formally tested, you can get a rough idea with a home blood pressure monitor. Lie down and rest for five minutes, then take a reading. Stand up and take another reading at one minute and again at three minutes. Write down both the blood pressure values and any symptoms you notice. Repeat this on several different occasions, since orthostatic hypotension can vary throughout the day and is often worse in the morning, after meals, or in hot weather.
Bring those readings to your appointment. A pattern of consistent drops meeting the 20/10 mmHg threshold gives your clinician solid data to work with and may reduce the need for repeated in-office testing. Note the time of day, whether you’d eaten recently, and what medications you’d taken, since all of these influence the results.