Swelling in one leg, especially if it starts suddenly
Pain or tenderness in the leg, often in the calf
Warmth in the affected area
Red or discolored skin on the leg
Leg cramps or aching that do not go away
Pain that worsens when standing or walking
One leg appearing larger than the other
Visible surface veins that seem more prominent than usual
Shortness of breath
Chest pain that may worsen with deep breathing
Rapid heartbeat
Coughing up blood
Seek urgent medical care if you have these symptoms, especially after recent surgery, long travel, pregnancy, or if you have a history of blood clots