Sports Entertainment Scoops (sescoops.com) is reporting that WWE Superstar Edge was diagnosed with spinal stenosis, which forced him to retire from active competition inside the ring.
Spinal stenosis is a narrowing of the spinal column that causes pressure on the the spinal cord. The condition is usually genetic in nature, and usually doesn't cause problems for people until they reach their 70's.
Spinal stenosis also ended the career of WWE Hall of Famer, "Stone Cold" Steve Austin.
With spinal stenosis, the risk of paralysis from taking a bad bump is high, and any type of regular in-ring performing would accelerate potential health problems, and adversely affect the performer's overall quality of life.
Even though Edge and Austin have ended their careers as in-ring performers, there is still a risk of worsening health problems.
Hopefully, retirement will allow them both to recover and have normal lives.
I have included a link to PubMedHealth.com which explains about spinal stenosis, it makes for interesting reading and will help to understand why Edge had to end his WWE career.