What's a 'silent' UTI? Experts explain.

Silent UTI
Silent UTIs barely leave behind any clues that there's an infection. (Photo Illustration: Victoria Ellis for Yahoo News; photos: Getty Images)

Believe it or not, you may have a urinary tract infection (UTI) and not even know it.

UTIs are common infections typically caused by bacteria that reside in the urinary tract and usually lead to a handful of unpleasant symptoms, including pain or burning during urination, bloating or discomfort in the lower abdomen, blood in the urine, the need to urinate frequently and/or feeling the need to urinate even though the bladder is empty.

However, there is a type of UTI that barely leaves any clues.

A “silent” UTI, otherwise known as asymptomatic bacteriuria, is a condition in which bacteria is found in the urine during a urine culture, yet the patient is not experiencing any of the classic UTI symptoms. Here’s some insight on this lesser-known infection.

What causes silent UTIs?

According to a 2022 review published in the American Journal of Medicine, asymptomatic bacteriuria tends to occur in at least 15% of older women; researchers from Louisiana State University School of Medicine found that cases were more prevalent in adults beginning at age 65, and the rates increase with age.

While the causes can vary, hormonal changes are the likely culprit.

“Starting in perimenopause, which can begin as early as 10 years before menopause, there is a decline in estrogen levels,” Dr. Corinne Menn, medical adviser to Alloy Women's Health, tells Yahoo Life. She explains that estrogen receptors, which are proteins within cells that bind to estrogen, can be found throughout the body, including in the genitourinary tract (which involves the bladder, urethra, vulva and vagina), and the loss of estrogen within these receptors is the primary cause of the progressive decline in women's urinary health.

“It results in thinner, drier and less resilient tissue, as well as a less elastic bladder and urethra, resulting in an increased infection risk,” says Menn.

There are other changes taking place in the vagina, such as a shift in the vaginal microbiome — microorganisms that reside inside the vagina — that may boost the chances of postmenopausal women developing a bacterial infection. The reason: “Good” bacteria — the kind that destroy bad-UTI-causing bacteria — can only grow in a slightly acidic vaginal environment, which requires some estrogen, according to the Urology Care Foundation.

As with any UTI, engaging in sexual activity can make it easier for bacteria to enter the bladder in women, says Menn. Other risk factors of silent UTIs include pregnancy, living with diabetes, having a urinary catheter in place and having undergone a surgical procedure in the urinary tract, according to Icahn School of Medicine at Mount Sinai.

What are the subtle signs of a silent UTI?

In many cases, there are absolutely no symptoms, yet some women may be dealing with a few seemingly unrelated health issues, Dr. Jennifer Caudle, a family physician and associate professor at Rowan University, tells Yahoo Life.

“Sometimes UTIs can simply present with atypical symptoms, such as confusion or changes in behavior, fatigue or decreased appetite,” she says. “In fact, this is something I’ve seen quite frequently in the elderly.”

A few other changes that may indicate a silent UTI include a slight increase in urinary frequency and urgency, subtle feelings of increased pressure or cramping in the bladder area and/or cloudy or blood-tinged urine, says Menn. Another sign can be urine with an ammonia-like odor.

If the UTI progresses, the signs will unlikely remain silent. Fever, chills, lower back pain, nausea and/or vomiting can indicate it has progressed to a kidney infection, according to the Centers for Disease Control and Prevention.

How should a silent UTI be treated?

It depends. If someone isn’t experiencing symptoms, treatment is unnecessary, states Mount Sinai, with some exceptions, such as if you’re pregnant or have kidney stones.

A study published in JAMA International Medicine found that treating asymptomatic UTIs with an antibiotic was not associated with an improvement in patient outcomes and was linked to longer hospital stays. A review published in the American Journal of Medicine concurs and adds that unnecessary antibiotic treatment was found to be associated with increased antibiotic resistance, which could cause future health complications.

But if the UTI produces symptoms and remains untreated, it could lead to a kidney infection (called pyelonephritis) and even cause sepsis. “It is one of the most common reasons for emergency room visits and hospitalizations for older women, which puts them at further serious health risks,” says Menn.

The Urology Care Foundation recommends practicing prevention strategies to ward off UTIs — the silent ones and the not-so-silent ones — such as urinating often, cleaning the genital area regularly, peeing before and after intercourse and drinking plenty of water throughout the day.

Taking cranberry supplements (or drinking cranberry juice) can also significantly reduce the risk of developing UTIs by preventing E.coli, the bacteria that most commonly cause these infections, from sticking to the bladder. Some research shows that taking another supplement, D-mannose, is a promising alternative to antibiotics to treat UTIs and also helps prevent infections by creating a “nonstick surface” along the bladder wall to prevent bacteria from latching on.