What happens if a male does not treat his uti?

Could prog to kidney: It not treated there is the possibility of it spreading up from the bladder to the kidneys and causing a more serious type of UTI called pyleonephritis.

Same as a woman: Agree with above. If a male or female ignores a uti, besides being uncomfortable is potentially dangerous and life-threatening if the infection ascends to the kidney and or to the blood (sepsis). Symptomatic utis (when diagnosed by urine culture) should be treated. See your primary doctor or urologist.