The spine as you know is a set of small blocks of bones arranged one on top of the other to form a pillar support for the body. Now these blocks of bones and connected to each other by spongy cushions called discs between them. At the posterior part of the pillar and behind the discs we have the spinal cord
running down from the neck to the tail region.
In your report, the disc at L4-5 (lower back) is showing some degenerative changes. Further there is a slight increase in the posterior transition of the disc at that level.
At L5-S1 level, the disc might have got fragmented due to degenerative process.
For you it means that if the pain is severe and unbearable, please let your doctor know and they will guide you towards a pain free future.
Hope this helps.