Female elderly patients, suddenly unable to urinate, then the possible causes: 1, neurogenic bladder, if the elderly suffer from various neurogenic diseases, cerebral hemorrhage, cerebral infarction, severe cerebral atrophy, etc., or suffer from diabetes mellitus, poor blood sugar control, etc., and cause a decrease in the function of the nerves governing bladder contraction, there is a failure of contraction of the detrusor muscle. In this case, a large amount of urine is retained within the bladder and cannot be discharged, so indwelling catheterization is required to deal with it.2. Urine cannot be discharged from the bladder because of the decrease in bladder contraction function in elderly patients, and the onset of the disease is usually slow. Because of the muscle contraction weakness after ageing, in addition to bladder muscle contraction weakness, it is also accompanied by limb muscle contraction weakness. If you are bedridden for a long time, muscle atrophy, etc., it can lead to the inability to urinate.3. If you have urethral stones or urethral tumors, it can lead to mechanical obstruction of the urethra, which leads to the inability to urinate. In this case, the presence of stones or tumor lesions in the urethra is seen during the examination, and further surgical treatment is required after temporary indwelling catheterization.