Symptoms of a blood clot in the leg

Blood clots in the legs are a relatively common disease, such as venous lower limb thrombosis, which is quite harmful to patients. It can easily lead to mobility problems, swelling of the legs, pain, etc. It can also cause increased tissue tension, edema, changes in skin color, and even lead to necrosis of leg tissues in severe cases. Therefore, timely treatment is necessary to avoid pulmonary acid embolism and life safety.

Symptoms of a blood clot in the leg

1. Swelling of the affected limb:

This is the most common symptom after lower limb venous thrombosis. The tissue tension of the affected limb is high and there is non-pitting edema. The skin color is reddish and the skin temperature is higher than that of the healthy side. When swelling is severe, blisters may appear on the skin. The location of swelling varies depending on the location of the thrombus. Patients with iliac-femoral vein thrombosis have obvious swelling of the entire affected limb; patients with calf venous plexus thrombosis have swelling only in the calf; patients with inferior vena cava thrombosis have swelling in both lower limbs. If the thrombosis starts in the iliac-femoral vein, thigh swelling will appear early. If it starts from the calf venous plexus and gradually extends to the iliac-femoral vein, the calf will swell first and then the thigh will be affected. The swelling is usually heaviest on the 2nd or 3rd day after onset and then gradually subsides. When the disease subsides, it first manifests as a decrease in tissue tension, and then a gradual reduction in the circumference of the affected limb, but it is difficult to return to normal unless the thrombus is completely removed early. In the later stage of thrombosis, although some veins have been reopened, the venous pressure in the affected limb is still high because the venous valve function has been destroyed, and its manifestations are similar to primary lower limb valvular insufficiency.

There are two main causes of pain: ① Blood clots cause inflammatory reactions in the veins, causing persistent pain in the affected limb. ② The blood clot blocks the veins, obstructing the venous return of the lower limbs, causing swelling and pain in the affected limbs, and the pain worsens when standing upright. Tenderness is mainly confined to the site of inflammatory response to venous thrombosis, such as the femoral vein or calf. Calf gastrocnemius tenderness is also called a positive Homans sign. Since squeezing the calf may cause the blood clot to dislodge, excessive force should be used during the examination. 3. Superficial varicose veins:

Superficial varicose veins are a compensatory reaction. When the main vein is blocked, the venous blood in the lower limbs returns through the superficial veins, causing the superficial veins to dilate compensatorily. Therefore, superficial varicose veins are generally not obvious in the acute phase and are a manifestation of the sequelae of lower limb venous thrombosis.

When DVT of the lower limbs extensively involves the intramuscular venous plexus, the iliac femoral veins and their side branches are completely blocked by blood clots, and tissue tension increases extremely, causing lower limb artery spasm, limb ischemia, and even necrosis. Clinically, it manifests as severe pain, shiny skin of the affected limb, accompanied by blisters or blood blisters, and the skin color is bluish-purple, which is called painful cerulea femoris. It is often accompanied by arterial spasm, weakened or absent arterial pulsation in the lower limbs, decreased skin temperature, and then a high degree of circulatory disorder. The patient has a strong systemic reaction, accompanied by high fever, mental weakness, and is prone to shock and wet gangrene of the lower limbs. 5. White swelling of thigh:

When acute deep vein thrombosis occurs in the lower extremities, lower extremity edema reaches its highest level within a few hours, the swelling is concave and high tension, and the obstruction mainly occurs in the femoral venous system. When infection occurs simultaneously, the stimulated arteries will continue to spasm, resulting in swelling of the entire limb, pale skin, and dilation of the subcutaneous venous network, which is called painful femoral leukoplakia.