POTS stands for Postural Orthostatic Tachycardia Syndrome. This condition results from a dysfunction of the autonomic nervous system – also referred to as dysautonomia. The autonomic nervous system controls all the body’s involuntary systems, like heart rate, blood pressure, and digestion to name but a few – which can all be affected in POTS.
The predominant diagnostic symptom is a sustained increase in heart rate of 30+ bpm upon standing up, that doesn’t go back to normal unless you sit or lie down (or faint – whatever comes first). For me, it feels like I’ve developed a freak allergy to gravity, which leaves me feeling very lightheaded, brain-fogged, occasionally nauseous – and like I REALLY need to lie down before I collapse. I often explain it to people in terms of being like a human hourglass; I can stand up until I feel like I don’t have much blood left in my top half, at which point I need to turn myself upside down (well, go and lie down) to refill myself. This is due to blood pooling.
Blood pooling is very common in POTS: you stand up, your blood pools in your legs. The heart beats faster to move the blood back up to your organs and brain – but fails to adequately achieve this. The end result as you slowly get starved of oxygen is feeling pretty shit, and in some cases fainting. Lying down helps to reset the balance. This endless cycle of dysautonomia every time you stand up, can cause other significant issues such as fatigue, brain fog, and digestive problems to name but a few.
I won’t go into more detail than that, as the POTS UK website does a much better job at explaining everything you need to know – and they have a number of very helpful leaflets you can find at Download PoTS Leaflets – PoTS UK