If your urine has a fishy smell, this isn't a hygiene problem and will not be solved with extra bathing or more showers. Fishy smelling urine is a common complaint among women as well as men.
I consulted with David H.C. King, M.D., Medical Director, Urology Services, El Camino Hospital Los Gatos. He explains, "Sometimes it can be difficult to tell if a 'fishy' smell is coming from the urine or the vagina The most common cause of a fishy smell is usually related to common vaginal infections such as trichomoniasis, gardnerella, or bacterial vaginosis."
If a man has a fishy smell "coming from" his urine, chances are, he may have picked up the bacterial infection from a woman he had sex with, who had trichomoniasis, or bacterial vaginosis.
Trichomoniasis is a sexually transmitted disease. This STD is curable (though reinfection is always possible after successful treatment), and 7.4 million cases are diagnosed yearly. Women can contract it from men and women, but men only contract it from women. Men usually don't have symptoms, but women often do (e.g., yellow-green vaginal discharge), including that fishy odor which may seem like it's coming from the urine, when in fact it comes from the vagina.
Gardnerella is also known as bacterial vaginosis, which is an overgrowth of the "bad" bacteria that are normally found in the vagina. Vaginal itching and irritation are symptoms, along with vaginal odor, which may be fishy, seemingly originating from the urine. In fact, this fishy smell is common with this condition.
Dr. King explains, "These conditions are easily treated with antibiotics. Sexual partners of these patients will also need to be treated. Condoms should be used until the antibiotics are completed."
Thus, if you're a woman who has been noticing a fishy smell coming from your urine, this unpleasant fishy odor is actually emanating from your vagina, and you should be checked by your gynecologist for a vaginal infection. Bacterial vaginosis and trichomoniasis are not life-threatening, and again, they are curable.
If you're a man who has noticed a fishy odor, have your physician examine you to see if you have picked up the infection from your sexual partner.
Being infected will not make you more immune or extra resistant to a future infection. Multiple sex partners increase your risk of these infections; a long-term monogamous relationship with a partner who has tested negative will go a long way in helping prevent these infections -- and thus, a fishy smell "coming" from your urine.