A blood clot is a mass of blood that changes from liquid to a gel-like or semisolid state. Clotting is a necessary process that can prevent you from losing too much blood in certain instances, such as when you injure or cut yourself.➡️Deep vein thrombosis (DVT) is a clot that occurs in one of the major veins deep inside your body. It’s most common for this to happen in one of your legs, but it can also happen in your arms, pelvis, lungs, or even your brain.An immobile blood clot generally won’t harm you, but there is the chance that it could move and become dangerous. If a blood clot breaks free and travels through your veins to your heart and lungs, it can get stuck and prevent blood flow. When it travels to your lungs, it’s called a pulmonary embolism (PE), which is a medical emergency.