How can you get multiple slipped discs?

Aging. By slipped discs, i assume you mean bulging and herniated discs. This is parts of the normal aging process. By age 60, approximately 90% have degenerative discs, 709% have bulging discs, and 36% have herniated discs in their lower back. So the answer, is if you live long enough, you will most likely have multiple degenerative discs.