Unlike a muscle cramp in your calf, a blood clot in your leg--a deep vein thrombosis, or DVT--requires emergency medical attention as a potentially life-threatening problem. People who suffer blood clots sometimes confuse the symptoms with those of muscle cramps in the calf. Approximately half the people with blood clots in the leg experience no symptoms at all or no symptoms until the clot breaks loose and travels to the lungs. If you suspect a blood clot in the leg, seek emergency medical care immediately.
If present, symptoms of a blood clot in the leg will typically include swelling of the leg or along a vein in the leg, pain or tenderness that you may feel only when you stand or walk, increased warmth in your painful leg, and redness or skin discoloration, according to the National Heart Lung and Blood Institute.
Many conditions that cause cramping give rise to cramps in more than one place, including in both legs. You can sometimes differentiate between a calf muscle cramp and a blood clot if you notice symptoms in only one leg. In addition, a cramp, while painful, will not generally cause redness, warmth or swelling, and a cramp will usually go away on its own. You cannot "walk off" the pain of a blood clot as you can that of a muscle cramp.
General Risk Factors
Knowing your risk factors for a clot may help you decide whether you need immediate emergency medical attention or suffer from only a calf muscle cramp. If you are at risk and have symptoms, suspect a blood clot. If you are overweight, smoke or have a history of blood clots, you carry more risk than the average person, according to Medline Plus.
Certain medications raise your risk for blood clots. If you take birth control pills or other hormone treatments, your blood clot risk rises. Other risk factors include certain cancer treatments, inactivity for any reason, recent injury, current or recent pregnancy, age over 60 or having a central venous catheter.
Illness or Injury
Fractures raise your risk of a clot, as do heart problems and some diseases, such as polycythemia vera, that cause blood to clot more easily. Untreated infection that causes a blood infection raises your risk for developing clots. If you have symptoms that make you suspect a blood clot, do not delay treatment. Quick diagnosis saves lives.