Thigh Pain When Driving My Bf Has Had INTENSE Upper Thigh Pain That Has Had Him Limping For Over A Week?

My bf has had INTENSE upper thigh pain that has had him limping for over a week? - thigh pain when driving

A severe pain in the thigh, going to your area of the buttocks and lower back ... The more than one week and still not have been better: (it hurts when he walks drives, if only to feel that can not play much, the pain is terrible, not even to school or work tomorrow .. I told him to fetch him, but notes that he wants to wait and see if it improves on its own. .. Has anyone an idea of which are what?
Thank you.