What Is Postural Orthostatic Tachycardia Syndrome (POTS)?
Postural orthostatic tachycardia syndrome (POTS) is a disorder that can make someone feel faint or dizzy. It happens when the autonomic nervous system (ANS) doesn't work as it should. The autonomic nervous system is the body's "autopilot" system, controlling things like heart rate, blood pressure, and breathing.
The autonomic nervous system problems seen in POTS (also called postural tachycardia syndrome) can affect children and adults. Symptoms vary from mild to disabling.
What Happens in Postural Orthostatic Tachycardia Syndrome (POTS)?
The autonomic nervous system keeps blood pressure at the right level for the brain no matter what position a person is in — standing (vertical), lying flat on the back (called supine), and sitting or reclining (called recumbent).
Usually when a person stands, the nerves of the autonomic nervous system tell blood vessels in the lower body to constrict (tighten). The tightening vessels work against gravity to keep blood from collecting in the legs. This automatic response makes sure the brain has enough blood flow to work well. If there is not enough blood flow to the brain, a person may feel lightheaded or pass out every time they stand.
In POTS, the autonomic nervous system doesn't work in the usual way, so the blood vessels don't tighten enough to make sure there is enough blood flow to the brain. To try to keep enough blood flowing to the brain, the autonomic nervous system makes the heart beat a lot faster instead.
What Are the Signs & Symptoms of Postural Orthostatic Tachycardia Syndrome (POTS)?
POTS is named for an unusual jump in the heart's beating speed that happens when a person stands. Other symptoms that can happen with POTS include:
- heart palpitations (feeling the heart beat or race)
- instability (feeling like one is about to fall)
- lightheadedness (almost passing out; vision tunnels or goes gray or dark)
- passing out (fainting)
- feeling tired
- chest pain
- trouble getting enough breath
- cold or painful extremities
- problems exercising
- redness or purple coloring in the lower legs
Most POTS symptoms happen only when standing or changing to a standing position. But these may happen without standing:
- sweating without a cause (such as exercise or warm weather)
- trouble concentrating
- trouble sleeping or unable to sleep (insomnia)
What Causes Postural Orthostatic Tachycardia Syndrome (POTS)?
POTS might first be noticed after a viral infection or an injury. But it's hard to tell if one of these caused POTS or just happened around the same time that POTS became a problem. Research to learn more about the cause of POTS is underway.
Who Gets Postural Orthostatic Tachycardia Syndrome (POTS)?
POTS affects more girls than boys, and is more common when one or both parents had POTS. It often begins in the early or mid-teens.
Teens with these disorders often have POTS too:
How Is Postural Orthostatic Tachycardia Syndrome (POTS) Diagnosed?
There's no single test to diagnose POTS. Doctors start by doing a complete physical exam and taking a medical history.
POTS causes a heart rate increase of 40 or more beats per minute within 10 minutes of when someone moves from a supine (lying down) position to a standing one. The heart rate goes up dramatically, with little if any drop in blood pressure. Doctors can measure this easily.
Sometimes, doctors do a "tilt-table test." In this test, a person is strapped to a table, then tilted from a supine (lying on the back) position into a standing position while heart rate and blood pressure are monitored.
Doctors also make sure the problem isn't due to anything besides the autonomic nervous system. Depending on the symptoms, tests might be done on other parts of the body. These might check the blood, heart, brain, eyes, ears, kidneys, muscles, nerves, hormones, digestive tract, and more. Typically, a diagnosis of POTS is confirmed when symptoms have lasted for several months and no other causes are found.
If someone has POTS, the medical team will look for reasons that the autonomic nervous system doesn't respond normally to standing. Finding an answer can help treatments work well.
How Is Postural Orthostatic Tachycardia Syndrome (POTS) Treated?
POTS is a chronic (long-term) problem. So doctors try to prevent and manage the things that cause it. That way, a child or teen doesn't have to take medicines for a long time.
Helpful treatments include:
- more water and salt intake
- better and longer sleep
- a slow increase in exercise, starting with seated, reclined, or horizontal exercises (such as rowing, recumbent bicycling, and swimming)
- wearing compression (squeezing) stockings
- raising the head of the bed so some pressure stays in the blood vessels in the legs during sleep
- psychological counseling to help manage stress and choices that trigger symptoms
The autonomic nervous system is involved in many body functions, so managing all the symptoms related to it can be hard. Sometimes, patients try a few different treatments to find what works well without unpleasant side effects. Multiple doctor's visits may be needed to find the best combination of treatments that improve symptoms.
POTS symptoms usually improve over time. Often, they'll completely disappear as kids grow. If a clear and treatable cause is corrected, the symptoms are likely to go away more quickly.