Assuming we're only talking about hunching over while sitting at the computer and not something more serious...

Stretch, Cronos. Speaking from experience, I have 2 severely herniated lumbar discs and spinal stenosis, which is a narrowing of the canal through the vertebrae which carries the spinal cord. Over the years, I've seen many therapists. Stretching is extremely important to your muscular and skeletal health, and yet is very often overlooked by most people.

When sitting at a computer (or sitting anywhere for long periods), every 30 minutes or so stretch. Like a cat, as a physical therapist once put it. Make both hands into fists and grasp the thumb of one hand in the other, push your arms straight out stretching your back and shoulder muscles. Then raise both arms into the air straight over your head and stretch again. Then rotate your arms in their sockets in a big wheel both clockwise and counter-clockwise. Now your neck. Turn your head to the right and look over your shoulder while keeping your shoulders straight. Repeat looking to the left. Do this three or four times each side. Now put your chin on your chest, or down in other words, and rock your head gently - gently! - back and forth. Feel the stretch between your shoulder blades. Tilt your head back and do the same. Make a habit of this routine and you'll feel much better during and after long computer sessions.

See a doctor. Don't take our advice as the gospel. And stretch!