Arterial and venous ulcers are differentiated clinically by close examination of the open sores. The characteristic features of arterial ulcers are: - Very deep wound - Hairless, taut skin - Red, yellow, or black discoloration - Leg pain at night - No bleeding The characteristic features of venous ulcers are: - Inflamed, swollen leg - Aching pain in leg - Itchy skin - Hard skin - Brown, black discoloration - Discharging wound Reference: https://www.healthline.com/health/arterial-vs-venous-ulcers#causes Image via: https://blog.wcei.net/venous-arterial-or-mixed-ulcer-how-do-i-know-for-sure