Postural orthostatic tachycardia syndrome (POTS) is a medical condition characterized by lightheadedness and palpitations in response to standing. With POTS, the heart rate increases dramatically with body position. Most people with POTS are women between the ages of 13 and 50.
https://www.verywellhealth.com/postural-orthostatic-tachycardia-syndrome-pots-1746386

