POTS, or postural orthostatic tachycardia syndrome, is diagnosed when your heart rate increases by 30 or more beats per minute within 10 minutes of standing up, without a significant drop in blood pressure. For adolescents (ages 12 to 19), the threshold is higher: 40 beats per minute. These symptoms must also be chronic, persisting for at least three to six months, and no other medical condition can better explain the heart rate spike.
Getting a POTS diagnosis can be a long road. Many people see multiple doctors over months or years before the condition is identified, partly because the symptoms overlap with so many other conditions. Understanding what the diagnostic process involves can help you advocate for yourself and know what to expect.
The Core Diagnostic Criteria
A POTS diagnosis rests on three pillars. First, your heart rate must rise by at least 30 bpm (40 bpm for teens) within 10 minutes of standing or being tilted upright. Second, this heart rate increase happens without orthostatic hypotension, which is a significant blood pressure drop. Orthostatic hypotension is defined as a drop of 20 mm Hg or more in the top blood pressure number, or 10 mm Hg in the bottom number, within two to five minutes of standing. In POTS, blood pressure typically stays relatively stable while the heart races.
Third, the symptoms must be chronic. A racing heart after standing that lasts a few days during a stomach bug or after a period of bed rest doesn’t count. You need to have been experiencing these episodes, along with symptoms like lightheadedness, fatigue, brain fog, or near-fainting, for at least three to six months.
What the Tilt Table Test Looks Like
The tilt table test is the most well-known diagnostic tool for POTS. You lie flat on a motorized table while connected to monitors that continuously track your heart rate and blood pressure. The resting phase lasts at least 10 minutes, giving your body a baseline. Then the table tilts upward to about a 70-degree angle (nearly standing) in roughly 10 seconds.
You stay in that upright position for up to 45 minutes while your provider watches how your heart rate and blood pressure respond. The test itself isn’t painful, but it can provoke the exact symptoms you experience in daily life: dizziness, nausea, a pounding heart, or feeling like you might faint. That’s actually the point. Your provider needs to see the abnormal heart rate response happen in a controlled setting where they can measure it precisely.
Not every diagnosis requires a tilt table test. Some doctors use an active standing test instead, where you simply lie down for several minutes, then stand up while they monitor your vitals with a blood pressure cuff and heart rate monitor. This approach is simpler and can be done in a regular office visit, though it’s less standardized.
Blood Work and Ruling Out Other Conditions
A heart rate that jumps when you stand isn’t unique to POTS. A long list of other conditions can cause the same thing, and your doctor needs to rule them out before landing on a POTS diagnosis. This is why many people feel frustrated by the process: it involves testing for things you don’t have before confirming what you do.
Common blood tests include:
- Complete blood count to check for anemia, which can cause a fast heart rate on its own
- Thyroid hormone levels to rule out an overactive thyroid
- Electrolyte panel to detect imbalances that could affect heart rhythm
Your doctor will also consider whether medications you take could be responsible. Stimulants, diuretics, and certain antidepressants (particularly those that affect norepinephrine) can all raise your standing heart rate. Dehydration, prolonged bed rest, severe anxiety or panic attacks, and adrenal gland problems are also on the list of conditions that can mimic POTS. If any of these fully explain the tachycardia, a POTS diagnosis is off the table until they’re addressed.
Identifying the Subtype
POTS isn’t one uniform condition. Some doctors, particularly those at specialized centers, will try to determine which subtype you have because it can influence treatment. The most commonly discussed subtype is hyperadrenergic POTS, where the sympathetic nervous system (your fight-or-flight system) is overactive. Up to 50% of people with POTS have elevated levels of norepinephrine, a stress hormone, when standing. A level of 600 picograms per milliliter or higher while upright points toward this subtype.
Testing for subtypes is more advanced and typically happens at specialized referral centers rather than in a general practitioner’s office. It may include measuring norepinephrine levels while lying down and again while standing, or assessing total blood volume to check for a condition called hypovolemia, where you simply don’t have enough blood circulating. These tests aren’t always necessary for a diagnosis, but they can help your care team fine-tune your treatment plan.
Which Doctors Diagnose POTS
There’s no single “POTS specialist” designation, which is part of why finding the right doctor can be difficult. Cardiologists and neurologists are the specialists most commonly involved in diagnosing and managing the condition. Cardiologists often run the tilt table test and evaluate the heart rate data, while neurologists may get involved when the autonomic nervous system (the system that controls involuntary functions like heart rate and digestion) needs more detailed evaluation.
Some major medical centers, like Johns Hopkins, run dedicated POTS programs with multidisciplinary teams that include specialists in physical medicine and rehabilitation, gastroenterology, neurology, cardiology, and adolescent medicine. These programs exist because POTS rarely affects just one system. You might have heart rate issues alongside chronic fatigue, digestive problems, and exercise intolerance, and coordinated care across specialties tends to produce better outcomes.
If your primary care doctor isn’t familiar with POTS, asking for a referral to a cardiologist or neurologist with experience in autonomic disorders is a reasonable next step. Many patients find that bringing their own heart rate data (tracked at home with a pulse oximeter or smartwatch, showing the difference between lying down and standing) helps move the conversation forward.
Why Diagnosis Takes So Long
The average time from first symptoms to a POTS diagnosis stretches well beyond what most people expect. Several factors contribute. The symptoms, including dizziness, fatigue, brain fog, and a racing heart, overlap heavily with anxiety, dehydration, and deconditioning. Many patients report being told their symptoms are stress-related before anyone checks their standing heart rate.
The three-to-six-month symptom requirement also means that even once a doctor suspects POTS, they may want to observe you over time before making it official. And because POTS often emerges after a triggering event (a viral infection, surgery, pregnancy, or a period of immobility), some providers initially attribute the symptoms to recovery from that event rather than recognizing a new chronic condition. If your symptoms have persisted for months and you notice a consistent pattern of feeling worse when upright and better when lying down, that pattern itself is valuable information to bring to your doctor.