There are several reasons why you may need to use an intermittent catheter, but fundamentally, if there is something affecting how the bladder sphincter or detrusor muscle (the bladder wall) functions, your body may need a little help to drain urine.
It is important to know, that if you do not self-catheterize per the guidance from your doctor, you may find that you start to leak urine when your bladder becomes too full. There may also be more complex challenges which require physician intervention. Choosing not to self- catheterize means you're leaving urine in your bladder for a long period of time, which can lead to a distended bladder or a urinary tract infection. An untreated urinary tract infection can spread to the upper urinary tract becoming more difficult to treat and more likely to spread to your blood causing sepsis. Sepsis can be life-threatening.
Speak to your healthcare professional to understand the implications for you and why intermittent cathing may be the best solution.