Urinary retention is a condition in which urine is stored in the bladder and cannot be expelled. There are many causes of urinary retention, so the first step in treatment is to find the main cause of urinary retention and to remove it to restore urination. If the cause cannot be removed temporarily, a catheter should be placed to drain the urine out of the body. It is one of the most common urological emergencies, with an urgent onset. Patients present with lower abdominal distension and pain, with an obvious urge to urinate, but are unable to do so, requiring urgent diagnosis and timely treatment. The main principle of its treatment is to relieve the cause of the disease and restore urination. The common causes of urinary retention are obstruction of the lower urinary tract, such as urethral stones, prostate enlargement, prostate cancer, urethral rupture; or caused by relaxation of bladder smooth muscle due to anesthesia after surgery and the use of certain drugs that relax smooth muscle such as scopolamine. Therefore, it is necessary to clarify the cause through urological ultrasound, CT and other examinations, and make appropriate treatment according to the cause and severity. If the cause cannot be clarified in a short time, a catheter can be used to drain the urine first. If it is difficult to leave the catheter in place, such as severe prostate enlargement or prostate cancer then suprapubic cystostomy can be done first to drain the urine. If the urinary retention is due to anesthesia or medication you can first apply a hot compress to the lower abdomen to promote urination.