Purple streaks on legs may be varicose veins, swelling streaks, etc. 1. Varicose veins: due to the restriction of blood flow in legs due to long standing and sitting for a long time, defective venous return function, resulting in blood stagnation in leg veins, purple streaks will appear in early stage, and curved stripes may appear in later stage as bumps. 2. Swelling stripes: common causes include excessive weight gain in a short period of time, excessive local volume growth or long-term high-dose application of glucocorticosteroids, etc., resulting in the breakage of subcutaneous elastic fibers and the production of purple stripes. Purple stripes on the legs may have other causes, such as accompanied by other symptoms, should be timely to the hospital, after a clear diagnosis to give targeted treatment.