Postural orthostatic tachycardia syndrome (POTS) is a chronic condition affecting the regulation of pressure that is most often seen after the onset of puberty. POTS results from a problem with the autonomic nervous system which controls “automatic” functions, or those that we don't have to think about. These functions include heart rate, blood pressure, body temperature, respiration and digestion.

Various studies suggest that more than 100,000 Americans have POTS. However, because of the complexity of symptoms and frequent misdiagnosis, this is only an estimate.

POTS was first identified as an illness in adolescents in 1999. Research has shown that approximately five times more females are affected by POTS than males. Some autonomic specialists believe that there may be an overlap between people with POTS and some people suffering from chronic fatigue syndrome.

What Causes POTS?

No one has defined a precise cause for POTS – it can result after a viral illness such as mononucleosis, triggering an imbalance in the autonomic nervous system. There may also be a genetic component as family members often report they had similar symptoms when they were younger.

What Are the Symptoms of POTS?

Symptoms can vary on a daily basis, but a classic finding in a person with POTS is an elevation of heart rate (tachycardia) upon standing (orthostatic intolerance), causing dizziness and palpitations. Also, a person with POTS may suffer extreme fatigue, difficulty concentrating, migraines, anxiety, tremors, nausea, insomnia and fluctuation in body temperature.

Many variations in the daily routine can aggravate these symptoms. For some people with POTS, lack of sleep, exposure to heat and humidity, simple changes in body position or standing can make symptoms worse.

Some days, a patient with severe symptoms will feel the need to lie down for the whole day. Many patients find themselves initially house-bound due to the symptoms. However, there are severe, moderate and mild cases of POTS. No two patients have the same severity of the syndrome, and no two cases respond to the same treatment.

POTS typically occurs after the onset of puberty and sometimes following a period of rapid growth. Patients can suddenly develop symptoms following a viral infection or severe shock.

How Is POTS Diagnosed?

Because of the number of heart-related symptoms, a cardiologist usually makes the definitive diagnosis. Although there is no specific test for the syndrome, diagnosis is made after performing an exhaustive medical history and physical examination. Awareness of the diagnosis of POTS is limited, and symptoms are often misdiagnosed, leading to a delay in diagnosis and treatment.

How Is POTS Treated?

Treatment primarily involves increasing fluid and salt intake, daily aerobic exercise, nutritional changes and, in some cases, medication. Treatment varies depending on the most prominent symptoms.

What Are the Long-term Effects of POTS?

In most cases, POTS slowly improves as young people enter adulthood. Almost all patients make a full recovery by early adulthood.