Women are more likely to develop a UTI because they have a shorter urethra than men, so bacteria has more of a chance to get into the bladder or kidney.
The most common reason why you might get a UTI is when the bacteria from poo enters the urinary tract.
Other reasons are sex, pregnancy, if you have a catheter inserted, kidney stones, dehydration, a weakened immune system and not keeping the genital area clean and dry.