Urinary retention to do the examination, including physical examination, laboratory tests, imaging tests and so on. 1. Physical examination: mainly for the examination of the genitourinary system, urinary retention is turbid on percussion, and there will be a feeling of urination and pain when you press between the navel and pubic bone with your hand. 2. Laboratory examination: including blood routine, prostate-specific antigen and so on. Blood test can assess whether the patient has proteinuria and diabetes. If the prostate-specific antigen is slightly elevated, it may also be related to acute urinary retention. 3. Imaging tests: including renal and bladder ultrasound, brain MRI or CT. Renal and bladder ultrasound can observe the amount of urine remaining in the bladder after urination, and can also determine whether there are bladder stones or urethral stones.