Pee with a strong fishy odor is most often linked to trimethylaminuria, a condition that causes trimethylamine to build up in the body and be released through urine and other body fluids. This buildup can create a noticeable odor from urine, sweat, breath, or vaginal discharge.
Pee that smells like fish may also be associated genetic factors that prevent the body from properly breaking down trimethylamine. The odor may also be triggered or worsened by certain medications, pregnancy, or foods that contain high levels of choline, such as fish, eggs, and some vegetables.
Although trimethylaminuria has no cure, the odor can often be managed with specific diet changes, medications to control intestinal bacteria, and products that help neutralize body odors. Medical evaluation is also important, as fishy-smelling urine can sometimes be confused with infections or other health conditions that require treatment.
What causes fishy-smelling urine?
Pee that smells like fish is typically the result of a condition called trimethylaminuria. Trimethylaminuria is caused by a genetic alteration that leads to a low levels of enzymes to breakdown trimethylamine in the body. This nutrient is typically found in fish, seafood, liver, peas and egg yolks. Without this enzyme, trimethylamine can start to accumulate in the body.
Some people may also experience smelly urine odors from medications, like tamoxifen, ketoconazole, and rosuvastatin. Odors that are noted after starting a new medication should be reported to the doctor.
Common symptoms
Pee that smells like fish can often be associated with a fishy odor exuded from other areas of the body. It can be noted in body fluids, sweat, breath, exhaled breath and vaginal discharge. Symptoms can be noted from infancy, when babies stop breastfeeding and start consuming solids. It can also worsen with adolescence, especially during menstruation or with the start of birth control.
People who have trimethylaminuria will usually take frequent baths, switch their clothes and even avoid social situations out of embarassment. This symptom can lead to the development of psychological disorders, like anxiety or depression.
Confirming a diagnosis
Trimethylaminuria is diagnosed through blood tests, a buccal swab and/or a urine test to determine the trimethylamine levels in these specimens.
Treatment options
This condition is not curable, and treatment is aimed at managing and reducing fishy odors. This can be done by decreasing intake of foods with high choline levels, like fish, seafood, mead, peas, beans, soy beans, nuts, egg yolks, kale, cauliflowers, brussel sprouts and broccoli.
It is important to remember that pregnant women should not limit certain items in their diet, as fish, for example, is important for fetal development and should be consumed normally.
Patients may also use antibiotics to control intestinal flora, which may also impact fishy smells. To neutralize odors, the doctor may recommend the use of soaps with a pH between 5.5 and 6.5, goat’s milk soaps, and skin lotions with a pH around 5.0. Frequently washing your clothes and consuming activated charcoal supplements as directed by a doctor may also be advised.