How common is degenerative disk disease (ddd) for men under 30? which races and professions are most susceptible?

Very common: Most people who are active have some degree of wear and ear (degeneration) somewhere in the body. Although conditions like ankylosing spondylitis, rheumatoid arthritis etc, are possible, they are rare. Weight loss, core-strengthening, stopping smoking, and proper lifting are often the best treatment for this common condition.

Degenerative Disk: Osteoarthritis and degenerative disk disease are very common but only about 1% of this disease occurs prior to age 30. The cause at this age includes old injuries, deformities, repetitive trauma from work or exercise, endocrine diseases, epiphyseal dysplasia, infection, and congenital bone abnormalities. White race has a higher incidence than black or Asian but numbers vary between studies.