Is there such a thing as mild crps (left leg)?

CRPS: Complex regional pain syndrome (crps) is a chronic pain condition most often affecting one of the limbs (arms, legs, hands, or feet), usually after an injury or trauma to that limb. Crps is believed to be caused by damage to, or malfunction of, the peripheral and central nervous systems. I assume if not moderate or severe pain, you could classify it as mild crps.

Yes: The signs and symptoms of crps can range from almost non-existent to completely disabling.