Ischemic foot, the lack of adequate arterial blood flow from the heart to the foot, can cause red discoloration when the foot is hanging down, according to PodiatryNetwork.com. Raynaud's phenomenon can cause fingers and toes to turn red, explains the National Institute of Arthritis and Musculosketetal and Skin Diseases.
Raynaud’s phenomenon is a disorder that causes the blood vessels, most frequently in the fingers and toes, to narrow when cold or feeling stress, according to the National Institute of Arthritis and Musculosketetal and Skin Diseases. Primary Raynaud's phenomenon, the occurrence of Raynaud's independent of any other illness, is the most common and typically occurs between age 15 and 25. Women and those living in cold places are more likely to have Raynaud's phenomenon than other groups.