Legs with long bags for no reason are commonly caused by the following reasons: first, varicose veins, often caused by long-term standing, weight-bearing or prolonged standing in water, when the bag is not large, you can reduce standing, reduce exposure to cold water, usually wear varicose socks to relieve the symptoms, when the bag is large, you need to perform surgery; second, hemangioma, often caused by trauma to the blood vessel wall damage, when the body increases blood pressure The disease can be clarified by checking the ultrasound of the lower limbs, and if it is the disease, it needs to be operated as soon as possible to prevent the rupture of the hemangioma; thirdly, sebaceous cyst, which is caused by the blockage of hair follicles, because it is an infectious disease, it needs to be operated; fourthly, caused by mosquito bites. In short, the leg lumps need to go to the hospital in time to clarify the cause.