degenerating

verb

decline or deteriorate physically, mentally, or morally.

the quality of life had degenerated

deteriorate,decline,sink,slip,slide,worsen,get/grow worse,take a turn for the worse,lapse,fail,fall off,slump,go downhill,regress,retrogress,decay,rot,go to rack and ruin,go to pot,go to the dogs,hit the skids,go down the tubes,go down the toilet,go to the pack,retrograde,devolve,waste away,waste,atrophy,weaken,become debilitated