Since clots block your blood flow, blood builds up behind the clot. This excess blood will cause swelling in the area around the clot.  Swelling is often the first symptom that you will notice. If your arm or leg is swelling but you haven’t injured yourself, then you may have a blood clot. In some cases, swelling can be severe in size. Blood clots can cause pain in the location of the clot, or, as in the case of heart attacks, which are caused by blood clots, displaced pain. The pain may feel like a cramp or charley horse. Unlike with a cramp, you will also experience other symptoms such as swelling and discoloration. Any blood clot can cause this type of pain, but it’s especially common with DVT. The pain will be severe and not relieved by over-the-counter pain killers. The skin around the swollen area may also have a reddish or bluish discoloration that looks like a bruise that won’t go away. If discolored skin is coupled with swelling and pain, then you should seek immediate medical attention. Blood clots cause your skin to be warm to the touch. Place your palm against your skin to feel the temperature. Compare it to the temperature of your forehead to determine if the skin over the potential clot feels warmer.  While the warmth may radiate just from the swollen part of your body, your entire limb could be warm.  In some cases, your skin may feel hot to the touch, rather than just warm. This symptom can be caused by all types of blood clots, including DVT, heart attacks, strokes, and pulmonary embolisms. You may not be able to lift your arm, walk, or speak. If you experience this symptom, you should seek medical care immediately.  At first, you may feel clumsy or like your legs are heavy. You may have difficulty speaking or lifting your arms. A blood clot in your lungs is called a pulmonary embolism. While they share many of the symptoms of blood clots in other parts of your body, they also include a few specific symptoms involving your lungs. Blood clots in the lungs usually have a sudden onset, so you may feel okay but then have symptoms. If you have any of these symptoms, you should call emergency services immediately:  A bloody cough. Lightheadedness. Excessive sweating. Chest pain or tightness. Difficult or painful breathing. Rapid or irregular heartbeat. with F.A.S.T. Blood clots are the most common cause of strokes. They often cause headaches, dizziness, trouble seeing, lightheadedness, and trouble walking. Since it’s important to get treatment quickly, you can use the acronym F.A.S.T. to easily identify a stroke.  Face- Look for one side of the face drooping. Arms - Check if the person can raise their arms and keep them up. Speech - Is the person’s speech slurred or strange? Time - If you notice any symptoms, act quickly and call emergency services. You’re more likely to develop a blood clot if you have risk factors for one. Knowing your risk factors could help you and your doctor determine if your symptoms could be a blood clot. This is particularly important in the early stages when your symptoms may not be that serious. Common risk factors include:  Obesity, pregnancy, smoking, surgery, and prior history of stroke. Prolonged sitting or rest, pulmonary embolism, DVT, and heart failure. Hiatal hernia, peripheral artery disease, polycythemia vera, and heart arrhythmias. Factor V Leiden, family history of blood clots, arteriosclerosis/atherosclerosis, and antiphospholipid syndrome. Certain medications, such as oral contraceptives, hormone therapy, and some breast cancer medications.

Summary:
Watch for swelling, especially in an arm or leg. Notice if you have pain in your shoulder, arm, back or jaw. Look for patches of discolored skin. Feel to see if your skin is warm. Watch for sudden weakness or numbness in your arm, leg, or face. Recognize symptoms of a blood clot in your lungs. Identify a stroke Know if you have risk factors.