What are reasons why symptoms of decompression sickness are often delayed?

Bends: If one doesn't ascend from depth (scuba diving) in a prescribed manner bubbles of nitrogen are trapped in the joints, soft tissues and arterioles causing pain symptoms. One then needs to undergo time in a decompression chamber where they take you down to depth and bring to sea level more slowly. Ask your PMD for referral to a dive specialist ASAP, if left untreated can have lasting ramifications