Thrombosis vs. Embolism: Symptoms, Causes, and Treatment

The most important way to prevent a blood clot in your body is to be proactive. Kateryna Kon/Shutterstock

Thrombosis and embolisms are different conditions, but they’re both characterized by a blood clot. Thrombosis happens when a thrombus, or blood clot, forms in a blood vessel. As a result, blood flow through the vessel is reduced. With an embolism, a piece of a blood clot (embolus), foreign object, or other bodily substance becomes lodged in a blood vessel. This largely obstructs blood flow.