There are many signs of a calf thrombosis, the main one being a painful change in skin color, which should be taken seriously, especially in patients who have recently had surgery and are bedridden for a long time. Calf thrombosis is divided into venous thrombosis and arterial thrombosis. Venous thrombosis is more common in people who have been bedridden for a long time and is predominantly swollen and may not have much color change. Surgery itself will cause local soft tissue damage, at the same time need long-term bed rest, can’t do local sports or whole body sports, circulation ability will be worse, the whole body metabolism is slow, it is easy to induce thrombosis. And arterial thrombosis can have dark color, pain and so on. The skin of the calf is usually dark, purple or red. Poor blood circulation can also cause muscle spasms, leading to increased localized pain or even pain throughout the affected limb. If a blood clot is suspected or any of these abnormal symptoms occur, you should go to the hospital as soon as possible. The diagnosis can be confirmed by a combination of imaging such as angiography, Doppler angiography, CT and blood tests.