In young individuals, the soft disc can slip (herniate) due to lifting heavy weight, excessive traveling, excessive bending work or sometimes there may not be any associated factor. In elderly patients disc become hard due to natural aging and due to disc dehydration and thus already has some tendency to bulge but the above precipitating factors can further contribute to the disc herniation. One common point seen in almost all patients is that they have weak back (spinal) muscles and they are unaware of back strengthening exercises. Smoking is also a contributing factor.
There are definitely some restrictions as after any other surgery but are very simple and easy to follow. For example, after lumbar surgery, it is taught how to get up from the bed and lie down, not to lift heavy weight, not to sit cross-legged. This is extremely important and explained with a diagrammatic chart and patients are expected to follow this for a few weeks.