At 17 yrs of age he is too young to have developed so many disc bulges. The symptom also suggests the compression of the nerve root
due to these bulges. Usually such changes are seen in elderly. In your son these are probably related to basketball playing and associated exercises. He may be an individual who is predisposed to this and aggressive playing has precipitated it. The predisposing factors could be in the form of abnormality of collagen
formation (there are diseases in which collagen protein s not formed normally and it can lead to musculoskeletal problems). He needs to undergo evaluation for that.