A Wells score ≤0 indicates low risk, 1-2 indicates moderate risk, and ≥3 indicates high risk; if both lower limbs have symptoms, the more severe side is considered. The probabilities of DVT for low, moderate, and high-risk patients are 3%, 16.6%, and 74.6%, respectively.

The Wells scoring system is a rule used for screening deep vein thrombosis, primarily based on the patient's medical history and physical examination to preliminarily determine whether the patient has high-risk factors for deep vein thrombosis.