If there are no contraindications to catheterization, girls 18 years of age can usually be intubated, i.e., with a catheter. Contraindications to catheterization in women include acute urethritis, menstruation, urethral stricture that prevents insertion of a catheter, or complete severance of a urethral injury. Catheterization is the insertion of a catheter through the urethra into the bladder to induce urine and is not a dangerous invasive procedure. Catheterization is mostly used in cases of urinary retention due to various lower urinary tract obstructions, resuscitation of critically ill patients, routine preoperative obstetrics, diagnosis and treatment of bladder disorders, urethrogram or cystography, retaining urine specimens for bacterial cultures, and probing the urethra for strictures. If the concern is whether a woman with no history of sexual activity can be catheterized, the answer is also yes, because the catheter enters the female urethra, not the vagina. The catheter is usually routinely lubricated prior to insertion to minimize patient discomfort, and the female urethra is shorter, wider, and straighter compared to the male, so there will be less discomfort. After the catheter is inserted, the patient needs to pay attention to prevent the catheter from falling out, drink plenty of water to prevent the urine from clouding the catheter, and keep the urine bag lower than the bladder behind the pubic bone to prevent the urine from flowing out, etc. The catheter is usually inserted by a specialized nurse. Catheterization is usually operated by professional nurses. If the patient is about to have a catheter inserted, it is recommended that he/she should not be too anxious and cooperate actively. If the patient is not feeling well, he/she should consult the doctor for examination and early treatment.