How can there be bruises on the legs in general, there are often the following reasons: 1, patients with localized falls, which will cause the rupture of subcutaneous capillaries, blood infiltration into the skin and tissue interstitial, manifested as subcutaneous bruising. At this time, due to the capillary blood volume is small, often can stop bleeding by itself. If you use local ice can promote capillary contraction, reduce blood extravasation. 24 hours later to give hot omelette local external application, is conducive to promote the absorption of bruises to play a better therapeutic effect; 2, local blood sampling patients did not press enough time, resulting in blood along the eye of the needle continued to seepage, resulting in localized bruising. Mostly seen in the femoral artery puncture, after the end of puncture, the patient’s compression of the puncture point time is less than 15 minutes. The pressure in the femoral artery is high, and the blood leaks into the subcutaneous tissue along the eye of the needle, causing bruising of the skin.