I am a 15 year old boy who has been dealing with chronically cold hands and feet, debilitating fatigue, and increase of symptoms after eating. In effort to test my self for POTS, I took my pulse lying down, then 10 minutes after standing. Lying down: 78 bpm After 10 minutes of standing up: 79 bpm Although my pulse did not increase, my hands and feet became a dark shade of blue, and were very cold. My lower legs became incredibly itchy. However, I did not experience an increase in fatigue while standing up. I have been tested for autoimmune disorders, thyroid problems, infectious diseases, diabetes/hypoglycemia, and many other diseases/conditions. I have been misdiagnosed multiple times in the past. I am 100% percent sure that my symptoms are circulatory related. It seems that something is preventing enough blood to reach my brain and lower extremities, causing these symptoms. What do you guys think??? What disorders would cause my hands and feet to become dark blue and itchy like that? Maybe something related to my heart? THANKS!