women get urinary tract infections more often than men. half of women have an infection at some point in their lives. it is common to have repeated infections. risk factors include sexual intercourse as well as family history. sometimes a person who had a bladder infection will get a kidney infection. kidney infection may also, but rarely, be caused by bacteria in the blood. diagnosis in young healthy women can be based on symptoms alone. sometimes, the urine needs to be tested. a person with frequent infections can take low-dose antibiotics to prevent future infections.