What is the risks of blood clots in ones leg and lung?

It depends: William, that depends on several factors. First, do you have any risk factors for blood clots? This includes recent hospitalization or surgery, recent travel, or prolonged sitting (like a truck driver). Second, do you have any family history of blood clots? Finally, do you have any symptoms? (leg pain or swelling, chest pain, shortness of breath). If the answer to all is no, then pretty low.

Deep vein thrombosis: William, the risk of superficial vein clot in leg is small. DEEP VEIN CLOT in LEGS IS EXTREMELY DANGEROUS and can cause clot to migrate to lung. This is pulmonary embolus and can cause sudden death. Lung clot on R.side of heart -same thing. LEFT side clot rarer, occurs in mitral valve disease and patent foramen ovale. Causes STROKE. MUST see an ER if suspected. BOTH needs anti-coagulation.