Version July 2025
| Clinical classification | |
| C0 | No visible or palpable signs of venous disease |
| C1 | Telangiectasias, reticular veins |
| C2 | Varicose veins |
| C2r | Recurrent varicose veins |
| C3 | Edema |
| C4 | Changes in skin and subcutaneous tissue secondary to chronic venous disease |
| C4a | Pigmentation or eczema |
| C4b | Lipodermatosclerosis or atrophie blanche |
| C4c | Corona phlebectatica |
| C5 | Healed |
| C6 | Active venous ulcer |
| C6r | Recurrent active venous ulcer |
| S | With symptoms attributable to venous disease |
| A | Absence of symptoms attributable to venous disease |
Limbs in higher categories have more severe signs of chronic venous disease and may have some or all of the findings defining a less severe clinical category. Each limb is further characterized as asymptomatic (C0-6, A) or symptomatic (C0-6, S).
Symptoms that may be associated with telangiectatic, reticular, or varicose veins include lower extremity aching, pain, and skin irritation. Therapy may alter the clinical category of chronic venous disease. Limbs should therefore be reclassified after any form of medical or surgical treatment.
