Causes of cold feet
Q. My feet are always cold, especially when I go to bed. Could I have a problem with my circulation?
A. Two of the most common causes of cold feet are decreased circulation in the extremities or a problem with nerve sensation. One cause of decreased circulation is atherosclerosis, where arteries are narrowed by fatty deposits and impede blood flow in the limbs. As a result, your feet may appear blue or purple when you are sitting, and pale or white when you are lying down. You may feel pain in your calves when you walk. Your doctor can usually detect this condition (peripheral artery disease) by checking the pulse in your legs.
A different circulation problem arises when small blood vessels constrict to conserve heat in the body. People who have less body fat (and therefore less insulation) need to conserve more heat, so the feet become cold to keep the internal organs warm. In Raynaud's syndrome, the small blood vessels overcompensate for cold temperatures. This may make the feet feel cold, and appear blue and then white. In response to warm temperatures, the feet then turn red. Some medications, including beta blockers, can mimic this response.