Sometimes my toes on my right foot get really cold. could this be a blood clot?

Decreased blood flow: A person with on and off cold fingers and/or toes usually has occasional decreased blood flow to his hands/feet. This is not from blood clots, but is due to the temporary contraction of little arteries carrying blood to the hands/feet. The arteries relax and widen later, and the hands/feet warm up again. A primary care doctor or rheumatologist can evaluate, as it could be an autoimmune disorder.

Not a blood clot: But it could be raynaud's phenomenon. I agree with dr. Kwok about seeing your doctor.

Possible: Cold toes or feet can be caused by a lot of things, including exposure to cold, peripheral vascular disease, specifically arterial disease, where enough blood doesn't get down to the tissues in the toes. Raynaud's is another cause. Sometimes an injury or compression of a nerve in the lower back causes decreased feeling causing a cold sensation in the foot. Blood clots are not the most common cause.