Knee tendons are obvious considering that the superficial veins around the knee joint appear thickened and tortuous, causing the veins to bulge on the skin surface, which is manifested as obvious tendons, and can also be manifested as green veins that can be seen walking through the skin. There are several common reasons for this condition: First, it is seen in people who often exercise, work out or work with high physical load for a long time, because the muscles of the lower limbs are more developed, the prolonged stress exercise causes the veins to grow and thicken, thus the phenomenon of bruising is obvious. Secondly, varicose veins in the lower limbs, due to poor blood return and venous stagnation, the prolonged stimulation will appear thickening and tortuous veins. Thirdly, it is seen in some inflammatory stimulation, which leads to the corresponding thickening and tortuosity of the veins.