Not an M.D., but here goes:

First, L4-L45 refers to the disc between your 4th and 5th lumbar vertebrae. Part of the disc at this level is bulging out backwards. It does not protrude far in a front-to-back direction, but is broad (left to right direction). The bulge is slightly greater to the right than to the left. You have some overgrowth of the bony structures adjacent to the spinal canal (facet joint hypertrophy) on the left. The bulge makes contact with the structure that holds nerve bundles at this level (thecal sac), but does not actually pressure the nerve bundles or narrow the channel in which they sit. The opening through which your L4 nerve root passes is narrowed a little bit ( left foraminal narrowing).

At the next lower level, L5-S1, there is also a disc bulge that narrows the channels for the L5 nerve roots on both sides. These openings are narrowed on both sides, right slightly worse than left. You have some bone spurs, worse on the right, that contribute to the narrowing, and also have some arthritic changes to the facet joints on both sides (bilateral facet joint arthropathy). These all combine to put pressure on your L5 nerve roots on both sides, with the right slightly worse than the left.

Bottom line is that you have some degenerative changes to your lower spine, with the L5-S1 area likely being the cause of your symptoms. I would consult a spine specialist, who will likely put you on a course of physical therapy and medications.

Good luck!

Jeff