When a nurse asked Tru for a second opinion on a middle aged patient with leg pain. Tru suggested that he might have a DVT. DVT is short for a Deep Vein Thrombosis, which is basically a very big clot in the leg. But these generally only occur in older patients. Other possible causes are surgery, recent trauma, or excessive strain on the leg (such as travelling). But smoking is not a possible cause for a DVT.