If a woman's urine has a foul odor, the possible causes range from recently eating asparagus or other foods to a vaginal infection to a collection of rare diseases, notes Columbia Health. If the odor lasts more than a day or two, it's wise to seek medical attention.
Asparagus is just one of several foods that lead to an unpleasant odor in the urine. Dehydration leads to a high concentration in the urine, making it a deeper yellow and giving it a strong scent. Various types of infection can cause urine odor as well. Trichomoniasis is a vaginal infection that creates a fishy, foul odor that emerges with urine and at other times as well. Gardnerella is another infection of the vagina that can lead to an unpleasant smell. In both cases, antibiotics provide the best treatment. Sex during this time should take place with a condom, as antibiotics counteract birth control, and infections can pass from one person to the other, notes Columbia Health.
There are some severe medical conditions that also can cause smelly urine in women. These include liver failure, rare diseases such as maple sugar urine disease, phenylketonuria and ketonuria, and an anomalous link between the bladder and rectum known as rectal fistula. The potential for serious conditions, combined with the need to get infection out of the body, is the reason for seeking medical attention if the odor remains after a few days.