Deep-vein thrombosis (DVT) is a blood clot that forms in a vein deep inside the leg or pelvis. It can sit like a plug or break off and travel to the lung, so early recognition is lifesaving. Sudden calf pain is the headline. It feels like a deep cramp or “charley horse” that doesn’t ease with stretching or massage. One-sided swelling shows up fast. The ankle or whole lower leg puffs, so socks leave a tight groove on the affected leg only. Warmth and redness appear. Skin over the vein feels hot and looks pink or purplish, like a localized... Learn more