Clinical Presentation

Symptoms and signs are variable at presentation and no single symptom or sign is pathognomonic of DVT. Presenting features are related to the effects of outflow obstruction and local inflammation. However, adaptation of venous collaterals and variable levels of inflammation mean that the degree of thrombus formation (i.e. the “clot load”) is frequently unrelated to the clinical findings.

Typical features related to the presenting complaint elicited in the history and examination are:


Pain is present in approx 50% of patients.


Swelling/oedema is usually unilateral and the most common sign. Ischaemic change is rare.

Homan’s sign

Homan’s sign (pain in the calf upon dorsiflexion of the foot) is unreliable and is often present in calves without DVTs. Anecdotally it may release thrombus into the proximal circulation.


Warmth and erythema can occur in an affected calf over the area of the thrombus.


Local tenderness is frequently present, though bears little correlation to the location or extent of thrombus.

Respiratory symptoms

A significant number of patients with a DVT first present with respiratory symptoms: 50% of patients with proven PE are subsequently shown to have a DVT.

Risk factor evaluation: 

A careful history searching for relevant risk factors is crucial in determining the most appropriate strategy for investigation; risk factors have been described in the previous section. These are combined with clinical features on presentation to complete a formal risk stratification of patients with suspected DVT (see later section).