| Class | Clinical Signs |
| C0 | No visible or palpable signs of venous incompetence |
| C1 | Spider veins and/or reticular varices |
| C2 | Varicose veins |
| C3 | Oedema |
| C4a | Pigmentation, eczema |
| C4b | Atrophie blanche, dermatoliposclerosis |
| C5 | Cured venous leg ulcer |
| C6 | Active venous leg ulcer |