Brief Answer: It may be a bad circulation Detailed Answer: Hi, I have gone through your query. As you have mentioned your father's feet and legs are turning purple and right leg is cold to touch. At present this is difficult to say about the cause. There are various causes of it, which may include: Cold (Raynaud's Disease) Blood clot in deep veins( Deep Venous Thrombosis) Compression of veins due to some chemical trigger. Peripheral Vascular disease. Purple or blue coloring to hands or feet usually means decreased or slowed circulation to the area. It is necessary for him to see a Vascular doctor for Complete clinical examination of the affected area and investigations like Complete Blood Count and Venous Ultrasound. Treatment may vary from use of compression Stalkings, medicines to surgery(stent) depending upon the investigation reports. Hope I have answered your query. If you have any further questions I will be happy to help.

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