Whether the glomerular filtration rate of 45 ml/min can be recovered needs to be determined according to the duration of the disease and whether it is treated in time. If the decreased glomerular filtration rate is caused by acute kidney injury, some patients may recover after timely treatment. If the decrease in glomerular filtration rate lasts for more than 3 months, it is a chronic kidney disease and usually will not return to normal. 1. Acute kidney injury: it is categorized into pre-renal, renal and post-renal. Pre-renal, such as insufficient effective circulating blood volume, may return to normal after rehydration and other treatments; post-renal, such as stones, may also return to normal after lithotripsy and removal of obstructive factors. Renal such as drug-induced, serious condition, untimely treatment may not return to normal level. 2. Chronic Kidney Disease: It is usually difficult to restore the glomerular filtration rate to normal when it is caused by chronic kidney disease. The treatment is aimed at slowing down the progression of renal function and avoiding further deterioration of renal function, and the specific treatments include actively treating the primary disease, preventing and treating complications such as renal anemia, renal bone disease and symptomatic supportive treatment. If the glomerular filtration rate decreases severely, you should go to the hospital in time and improve the examination and systematic diagnosis and treatment under the guidance of professional doctors.