The annual incidence of the first episode of symptomatic DVT in the adult population ranges from 50 to 100 per 100,000 population, and the overall incidence of venous thromboembolism (VTE), including pulmonary embolism (PE) events, is about 25% higher. Epidemiology studies are either retrospective, using national or regional patient cohorts studied over several years, or prospective ultrasound-based studies performed over 1 to 2 years.

The incidence of DVT is slightly higher in women aged 20 to 45 years, but men have a higher incidence between 45 and 60 years of age. The incidence is higher for males across all age groups if female-specific risk factors (oral contraceptives and pregnancy) are excluded. The incidence increases twofold per 10-year age increase. Approximately one in 12 middle-aged adults will develop either DVT and/or PE in their remaining lifetime, and 60% of all VTE events occur in patients aged >65 years. African Americans have a higher incidence of DVT than Caucasians and Native Americans, whereas Asians (China and Korea) have a lower incidence. A seasonal variation occurs, with a higher incidence of VTE in the winter, peaking in February.

The rate of recurrent VTE is around 10% in the first year and 30% after 5 to 8 years for patients with unprovoked DVT without an identified triggering factor. The annual incidence of VTE has not changed in the last two to three decades, although the prevalence of cancer, major surgery, trauma, and obesity has increased. The widespread availability of improved diagnostic modalities with computed tomography (CT) and magnetic resonance imaging (MRI) has led to increased detection of incidental VTE in patients with cancer. Venography remains the gold standard for establishing diagnosis.