<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been experiencing poor circulation in my legs. I feel like my legs are always tired and achy. What could be the cause of this?  <response>: It sounds like you may have venous insufficiency, which is a condition where the veins in your legs have difficulty returning blood to your heart. This can lead to poor circulation and cause symptoms like leg pain and swelling. 