My feet often turn purple/blue when im sitting or standing. it doesn't bother me, no numbness, pain, tingling. what could cause this?. im 23.

Circulation problem?: Purple or blue coloring to hands or feet usually means decreased or slowed circulation to the area. This can happen if the blood vessels get compressed or if the vessels tighten themselves and lessen the blood flow. Sometimes, blood flow will change due to nerve signals or chemical signals telling the vessels to constrict. A primary doctor and a rheumatologist can evaluate and look for the cause.

Venous insufficiency: You may have superficial or deep venous insufficiency. I would recommend seeing a vascular surgeon to identify the cause of this problem.