Americans have been warned from top experts to learn about and prevent deep vein thrombosis and pulmonary embolism.
The warning has come from Acting Surgeon General Dr. Steven K. Galson who has called for action in reducing the number of cases in the United States.
Dr. Galson says deep vein thrombosis and pulmonary embolism are preventable, treatable conditions which Americans need to learn about as they affect as many as 600,000 Americans each year - those numbers are expected to increase as the population ages.
Deep vein thrombosis and pulmonary embolism contribute to at least 100,000 deaths each year - deep vein thrombosis is a blood clot in a deep vein, most commonly in the lower leg or thigh which can block blood flow and cause pain, swelling, and skin discoloration.
The most serious cases can lead to a pulmonary embolism when part of the blood clot breaks loose and travels through the bloodstream to the lungs, where it can block a lung artery, causing damage to the lungs or other organs from lack of oxygen.
Dr. Galson says they are often 'silent' conditions which can occur suddenly and without symptoms.
He says substantial progress in understanding how the disorders develop and how to prevent, diagnose, and treat them, has been made and it is now time to put this knowledge into action.
Experts say in most cases, deep vein thrombosis and pulmonary embolism develop in people who have an inherited blood clotting disorder or other risk factor, and who also experience a triggering event.
Such an event includes recent surgery or a broken bone, a fall, a car crash or accident, pregnancy, taking birth control pills or menopause hormones and being immobile for long periods.
The risk rises with age, especially over 65, and is greater among people who smoke or are obese.