Hit hard by POTS

Gwen's heart starts racing as soon as she gets up from an afternoon nap, and she suddenly feels dizzy and weak. It's not the first time this has happened to her lately — just rising from a chair too quickly can necessitate sitting right back down again. But Gwen's symptoms don't seem to make sense; she's active and fit, in the peak of life.

For up to a million Americans — more than three-quarters of whom are women under 50 — the cause of this mysterious constellation of symptoms is postural orthostatic tachycardia syndrome, or POTS. Life-changing but not life-threatening, POTS can make it almost impossible to exercise. This can lead to sedentary behavior that only worsens symptoms, which can also include palpitations, lightheadedness, brain fog, fatigue, and blurry vision.

Common to many conditions, these symptoms can make POTS tricky to diagnose, says Dr. Anne-Marie Anagnostopoulos, a cardiologist at Harvard-affiliated Beth Israel Deaconess Medical Center. Fortunately, however, once that happens, the condition is "certainly manageable," she says.

"A common symptom is what's called orthostatic intolerance, meaning you're unable to tolerate being in an upright position, which of course can be incredibly debilitating," Dr. Anagnostopoulos says. "But POTS symptoms usually improve over time. This isn't a permanent state."

Common triggers

POTS occurs when the autonomic nervous system — which regulates involuntary bodily functions such as heart rate, breathing, and digestion — can't properly coordinate heart rate and blood flow changes that normally occur when someone changes position.

But scientists are still teasing apart what causes the syndrome and why women are predominantly affected. "There's some speculation how fluctuations of hormones around puberty, menstrual cycles, and pregnancy contribute to POTS," Dr. Anagnostopoulos says. "During certain parts of the menstrual cycle, for example, the heart delivers less blood to the body."

Size also matters. Women have smaller hearts than men, and our hearts pump out less blood with each beat. This can make it harder for women's hearts to supply blood and oxygen to the body when we're upright or exerting ourselves.

Other factors that temporarily raise your risk include

• viral infection, such as the flu or COVID
• surgery
• concussion
• a long period of inactivity.

"Common to those triggers is often prolonged bedrest," she says. "Patients can experience changes to their heart and blood flow that make it hard to tolerate being upright and getting back to normal activities."

Management strategies

Because its symptoms overlap with conditions such as chronic fatigue syndrome, anxiety, or panic disorder, POTS is sometimes misdiagnosed. Women are also more likely than men to wait longer before being diagnosed correctly, seeing an average of five doctors before this happens, according to a 2021 study in the journal CJC Open.

Various approaches can tease out POTS, including a physical exam and a tilt table test, which tracks how your body responds when you shift from lying down to standing up. Heart problems also need to be ruled out.

Once POTS is confirmed, doctors typically recommend several straightforward ways to manage symptoms:

Exercise. It may be the last thing you want to do when symptoms arise, but aerobic movement is a mainstay of POTS management because it boosts the body's ability to adapt to heart rate changes. Newly diagnosed patients are typically counseled to start a three-month structured exercise program that includes riding a reclining stationary bike, doing floor exercises, and swimming. "We build up from there as we retrain their nervous system to tolerate more upright exercise," she says, "and add weight training as well."

Drink more fluids. Dehydration reduces blood volume, leading to drops in blood pressure that can trigger dizziness and weakness.

Increase salt intake. This is one situation where consuming more salt is wise, since it helps your body retain water and boosts blood pressure. "If you like to drink a lot of water, do it while eating a handful of pretzels or saltines," Dr. Anagnostopoulos says.

Cross your legs. Sitting with one leg over the other or squeezing a rubber ball in your hands are examples of a principle called counter-pulsation, which can gently boost blood circulation.

Wear compression garments. Special stockings and leggings apply gentle pressure on the legs, supporting proper blood flow. "Compression therapy counteracts pooling of blood in the lower body," Dr. Anagnostopoulos says.

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