What Are Symptoms of a Blood Clot in the Knee?

By Staff WriterLast Updated Mar 27, 2020 6:46:53 PM ET
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Large blood clots in the legs can cause symptoms such as leg redness and warmth, leg swelling, and leg pain that worsens when standing up or walking, according to ClotCare. While blood clots located below the knee are unlikely to cause complications, clots that start or extend above the knee sometimes break away, travel through the blood and block blood vessels in the lungs, causing a pulmonary embolism.