What is the Wells score?
The Wells score is a number that reflects your risk of developing deep vein thrombosis (DVT). DVT happens when a blood clot forms in a vein that’s deep inside your body, usually in your leg. Your Wells score is calculated based on several factors. Using this score, your doctor can determine your likelihood of having DVT. This helps your doctor decide whether to proceed with further diagnostic testing, such as a CT scan.
Your doctor will check for several symptoms and risk factors. Each of these is assigned a point value. After evaluating you, your doctor will add up the points to get your Wells score.
Some doctors prefer to use their own modified version of a Wells score, so your doctor may use slightly different criteria.
| Symptom and risk factors | Points |
| Active cancer, or cancer that’s been treated within last six months | 1 |
| Paralyzed leg | 1 |
| Recently bedridden for more than three days or had major surgery within last four weeks | 1 |
| Tenderness near a deep vein | 1 |
| Swollen leg | 1 |
| Swollen calf with diameter that’s more than 3 centimeters larger than the other calf’s | 1 |
| Pitting edema in one leg | 1 |
| Large veins in your legs that aren’t varicose veins | 1 |
| Previously diagnosed with DVT | 1 |
| Other diagnosis more likely | -2 |
Your doctor will interpret your Wells score based on either a two-tier or three-tier model. If your score indicates you have a higher risk of DVT, your doctor might do additional testing, such as a venogram.
Two-tier model
| Score | Result |
| 2 or higher | DVT is likely |
| 1 or lower | DVT is not likely |
Three-tier model
| Score | Result |
| 3 or higher | High risk of DVT |
| 1 or 2 | Moderate risk of DVT |
| 0 or less | Low risk of DVT |
Your Wells score can help your doctor determine your risk of developing DVT. If your score indicates you have a higher risk, your doctor may suggest additional testing to look for a blood clot. If your risk is low, they may simply monitor you for any new symptoms.