Clinical catheterisation is an invasive procedure and indwelling catheterisation causes discomfort to the patient due to urethral irritation signs, therefore, most patients will feel nervous and anxious due to fear of pain.
Urinary catheterisation before general anaesthesia

Advantages: Inserting a urinary catheter when the patient is awake can inform the patient of the purpose of urinary catheterisation, how to cooperate and postoperative precautions, which can make the patient psychologically prepared and reduce the discomfort after waking up at the end of the operation.

Disadvantages: Most patients will be involuntarily nervous because they are unfamiliar with the operating theatre environment, and if this operation is carried out before the operation, it will aggravate their anxiety and fear.

Catheterisation after general anaesthesia
Advantages: Due to the effect of anaesthesia drugs, the patient's consciousness is suppressed, so the patient does not feel the discomfort caused by the insertion of a urinary catheter.
Disadvantages: Although there is no anxiety or discomfort before the operation, after the operation, with the metabolism of the drugs, the patient will slowly wake up, and at this time, due to the central nervous system of urination is still in a state of inhibition, coupled with the patient is not psychologically prepared, and thus will appear in the urinary tract irritation sign and feel uncomfortable or even agitated.