Risks associated with catheterization include:

• Urethral trauma and bleeding from inappropriate catheter size or use of force.
• Urinary tract infections related to poor sterile technique or long-term catheterization.
• Bladder spasms and pain  

Choosing the appropriate catheter depends on

• The size of the patient’s urethral canal
• The expected duration of catheterization (e.g. intermittent or indwelling)
• Knowledge of any allergies to latex or plastic.
• The indications for catheterizing the patient (i.e. clot retention, child, bladder instillation).