POTS can lie dormant until it is triggered by a virus, diabetes, growth spurt, etc. This illness is not studied in most medical schools and as its symptoms are so diverse, most people who have this are either misdiagnosed (often with anxiety) or not diagnosed at all. Sometimes POTS is called an "invisible illness" or "hidden disability" because patients may appear to be just fine.
POTS is different for each person. Symptoms of POTS can include any of the following: fainting or near fainting, chest pains, dizziness, headache, visual disturbances, insomnia, anxiety, shortness of breath, racing heart, joint pains, lower back pain, neck pain, fatigue, etc. These symptoms can be of varying degrees and can come and go at any time.
A pulse that goes up by more than 30 bpm (tachycardia) when changing positions (i.e. supine to standing) can determine whether a person has POTS. In many cases a tilt table test can provide an accurate diagnosis. If you're looking for more information, search also for Orthostatic Intolerance, Orthostatic Hypertension, the Postural Tachycardia Syndrome, Sinus Tachycardia, etc.
In terms of awareness, POTS today is what Autism was 15 years ago. Many people who have this syndrome are accused of being "hypersensitive, overdramatic, or hypochondriacal." This is just plain ignorance. POTS is real, it is awful, and it's time to raise awareness. POTS has only been recognized for the past decade. Most people, and most doctors(!) have not even heard of the syndrome.
This description is from a facebook group called POTS
http://www.facebook.com/?sk=2361831622#!/group.php?gid=75183049224
