My husband has numbness on his upper left thigh, what causes this? he is a drinker and smoker.

Pinched nerve: Numbness in upper thigh is usually caused by a pinched nerve near outer groin. The nerve is called lateral cutaneous nerve of thigh. It causes numbness, tingling and burning in the front and outer side of thigh. Condition is referred as meralgia paresthetica. Other possibility can be pinching of nerves in upper part of lower back.