However, because these products are not subject to rigorous oversight, supplement ingredients can vary in quantity or quality. And without the guidance of a medical professional, a patient may inadvertently take a supplement that interacts with their current medication. “The big problem with any of these things is quality control,” Dr. Brucker said.

Doctors aren’t completely certain why some people experience recurring U.T.I.s and others never have them. Those who frequently contract U.T.I.s are often prescribed low-dose daily antibiotics. For the general population, though, there are simple steps to help protect against these infections.

Basic hygiene is essential: Women should always wipe from front to back after using the toilet, to ensure bacteria from the rectum does not travel near the urethra. For both men and women, it is important to stay hydrated, and to urinate throughout the day — don’t try to hold it for uncomfortably long stretches, Dr. Higgins said.

During perimenopause and menopause, women may be at higher risk for U.T.I.s as estrogen levels decrease. Topical vaginal estrogen is the “gold standard” non-antibiotic treatment to prevent recurrent U.T.I.s in this population, Dr. Lowder said.

And, true to conventional wisdom, urinating after sex can reduce the risk of developing a U.T.I. by flushing bacteria out of the vagina, Dr. Rosen said, although evidence backing up the effectiveness of that habit is thin.

“There’s really no data for it,” Dr. Brucker said.

Doctors cautioned against assuming all vaginal irritation or pain is a U.T.I. Common U.T.I. symptoms can also indicate bacterial vaginosis, yeast infections, sexually transmitted infections, urinary incontinence and even bladder cancers. If a patient experiences the symptoms of a U.T.I., and especially if blood is present in their urine, they should seek a medical professional. If you don’t have a primary care doctor, urgent care centers can also diagnose U.T.I.s, Dr. Higgins said.