Blood clots are gel-like masses that form when blood cells and proteins stick together. They are a natural part of the body's healing process, helping to stop bleeding when injuries occur. However, when clots form inappropriately, they can lead to serious health issues, such as deep vein thrombosis or pulmonary embolism. Clots can develop in veins or arteries and may block blood flow, causing pain or swelling. Risk factors for abnormal clotting include prolonged inactivity, certain medical conditions, and some medications. It's important to recognize symptoms like swelling or sudden pain, as timely treatment can prevent complications.