Stroke and myocardial infarction are major causes of death. It is estimated that every 45 seconds, someone in the United States suffers a stroke. Annually, approximately 700,000 people experience a new or recurrent stroke; about 500,000 of these are first attacks, and 200,000 are recurrent. The estimated frequency of a heart attack is even greater: each year, approximately 1,200,000 people living in the United States will suffer from a new or recurrent myocardial infarction. In addition, it is estimated that there are 175,000 silent first heart attacks annually.

Venous Thromboembolism (VTE) is the term used to encompass both DVT and PE. The precise number of cases of VTE is uncertain because the diagnosis is often obscure or the disease may be asymptomatic or mimic other diseases. In the United States, estimates range from about 900,000 to 2,000,000 VTE cases per year. About two-thirds are DVT alone and about one-third are DVT plus PE or PE alone. The number of deaths is uncertain. Estimates of death rates per year vary from 50,000 to 300,000.

Annually, more individuals may die from DVT complications than from the combination of AIDS, breast cancer, and motor vehicle accidents combined.

Fatal PE caused by DVT may be the most common preventable cause of hospital death in the United States. Yet, only one-third of hospitalized patients with risk factors for venous blood clots receive preventative measures.