Blood clot symptoms will depend on where a clot forms in your body. Some people may experience no symptoms at all. Blood clots can occur in the: Abdomen: Blood clots in the belly area can cause pain or nausea and vomiting. Arms or legs: A blood clot in the leg or arm may feel painful or tender to the touch. Swelling, redness and warmth are other common signs of blood clots. Brain: Blood clots in the brain (strokes) can cause a range of symptoms, depending which part of the brain they affect. These clots may cause problems speaking or seeing, inability to move or feel one side of your body and sometimes seizure. Heart or lungs: A blood clot in the heart will cause symptoms of a heart attack such as crushing chest pain, sweating, pain that travels down the left arm, and/or shortness of breath. A blood clot in the lungs can cause chest pain, difficulty breathing, and sometimes can lead to coughing up blood.