Clinical manifestations of lower extremity venous thrombosis may include swelling and pain in the lower extremities depending on the course of the disease, and if the thrombus is dislodged, it may even cause fatal pulmonary embolism. According to the course of the disease, it can be divided into occlusive type, partially recanalized type and recanalized type. 1. Occlusive type: In the early stage of the disease, it can be manifested as obvious swelling and pain in the lower limbs, accompanied by dilatation of superficial veins. 2. Partial recanalization type: at this time, the swelling and distension of the lower limbs can be reduced, but the dilatation of superficial veins can be aggravated or superficial varicose veins can appear, at the same time, it can be accompanied by hyperpigmentation of the distal part of the calf. 3. Recanalization type: in the late stage of the disease, the swelling of the lower limbs is reduced but aggravated after activity; obvious varicose veins may appear; chronic recurrent ulcers and extensive pigmentation of the lower legs may appear. If there is any discomfort, it is recommended to consult a doctor in time for diagnosis and treatment.