K.O.
My husband had the same problem and it turned out to be a herniated disk. It isn't life threatening but the only thing he has found to ease the pain is prescribed medicine so you will most likely need to take him to a doctor. I've seen first hand how painful it is. If you can afford it, the doctor will most likely send him to a specialist like he did my husband and he can have a surgery done to fix the problem. My mother in law, and grandmother in law have both had it done and it worked wonders. My husband will have it done in a week. It's a simple procedure and is supposed to help.