Postural orthostatic tachycardia syndrome

Postural orthostatic tachycardia syndrome (POTS, also called postural tachycardia syndrome) is a medical problem. When a person has POTS, their heart beats faster than normal when they stand up. POTS may also cause many other symptoms.
Meaning.
Put together, the words "postural orthostatic tachycardia syndrome" mean that when a person stands up, they get tachycardia, and they also have other symptoms.
Signs and symptoms.
When a healthy person stands up, their heart beats faster for a little while. It does this to push blood to the brain. Then the person's heart rate goes back to normal.
When a person with POTS stands up, their heart beats much faster than normal. POTS is diagnosed when a person's heart rate increases by at least 30 beats per minute within 10 minutes after they stand up. This is called "postural tachycardia".
People with POTS also have other symptoms of "orthostatic intolerance" (symptoms that get worse when a person is standing up, and get better when the person is lying down). These symptoms may include: 
Symptoms may get worse if a person with POTS:
Causes.
POTS can be caused by many different things. Many of these causes are not well understood.
Some of the known causes of POTS include:
POTS is more common in:
Treatment.
There are many different treatments for the symptoms of POTS. Some of these treatments include:
No medications have been approved by the United States Food and Drug Administration to treat POTS. However, sometimes doctors treat POTS with medications that:
Recovery.
Most people with POTS are able to get better with treatment. About 6 out of every 10 people with POTS is able to recover within 5 years of being diagnosed with POTS. About 9 out of every 10 people with POTS have some improvement with a combination of physical treatments and medicines. 
However, some people with POTS do not get better, and may even get worse over time.