A 47-year-old male experienced a severe pain in the back of his left foot in 2004. Initially, he did not pay much attention, but the frequency of the pain increased after September this year, often occurring at night. He inquired whether it could be a sign of a disease and what precautions should be taken.

A vascular malformation refers to an abnormal vascular structure that remains after birth due to the failure of certain arteries or veins to close properly during the process of embryonic development.