What Is a Urinary Tract Infection?
If bacteria enter the urinary tract, they may begin to multiply, causing inflammation and irritation. This inflammation and irritation is a urinary tract infection (UTI). UTIs occur in the upper and lower urinary tract and can affect the urethra, bladder, ureters, or kidneys.
Anyone can get a UTI, but they are more common in women. Nearly half of all women will experience at least one UTI during their lifetime. Children can also get UTIs.
Anatomy of the Urinary Tract
The organs of the urinary tract are responsible for filtering waste products from the blood, maintaining electrolyte balance, and producing, storing, and eliminating urine. The urinary tract is made up of the following organs and structures:
- Kidneys: The kidneys are two bean-shaped organs located on either side of the spine, just below the ribcage. They are responsible for removing waste products and toxins from the blood. They also maintain the proper balance of electrolytes and water to produce urine.
- Ureters: The ureters are two muscular tubes that move urine from the kidneys to the bladder. Each ureter connects one kidney to the bladder.
- Bladder: The bladder stores urine until it is ready to be eliminated from the body. When the bladder is full, nerve signals are sent to the brain, triggering the urge to urinate. Then, the bladder’s muscular walls contract to push urine out during urination. This is usually a voluntary response, meaning you decide when this happens.
- Urethra: The urethra is a tube that carries urine from the bladder to the outside of the body. In females, the urethra is relatively short and located just above the vaginal opening. Males have a longer urethra which extends from the bladder to the tip of the penis. The urinary sphincters, circular muscles surrounding the urethra, control the urine flow and prevent leakage by contracting and relaxing as needed, typically only when you decide to urinate.
Each component of the urinary tract plays a specific role in maintaining proper urinary function and they each coordinate with each other when the system is operating normally.
Causes of UTIs
Urinary tract infections are typically caused by bacteria entering and multiplying within the urinary tract. The bacteria that most commonly cause UTIs are:
- Escherichia coli (E. coli): E. coli is a type of bacteria found in the intestines of humans and animals. Around 80–90% of UTIs are caused by E. coli, which can enter the urinary tract from the rectal area. This is especially true for women because of the proximity of the anus and the urethra.
- Staphylococcus saprophyticus: Approximately 5-15% of UTIs are caused by this bacteria. Staphylococcus saprophyticus can colonize the genital and perianal areas and enter the urinary tract, causing infections.
Less common bacteria responsible for UTIs include Proteus, Klebsiella, and Enterococcus species. These bacteria may cause UTIs in individuals with urinary tract abnormalities or weakened immune systems.
Risk Factors
Several risk factors can increase a person’s likelihood of developing a UTI. These include:
- Gender and age: Women are more susceptible to UTIs than men due to their shorter urethra, which allows bacteria to reach the bladder more easily. Additionally, the risk of UTIs increases with age, particularly for postmenopausal women who experience hormonal changes that can affect the lining of the urinary tract.
- Sexual activity: Sexual intercourse can introduce bacteria into the urethra, increasing the risk of UTIs. Women who are sexually active or have a new sexual partner are at a higher risk of developing UTIs.
- Urinary tract abnormalities: Structural abnormalities or obstructions in the urinary tract, such as kidney stones or an enlarged prostate, can impede urine flow, leading to a higher risk of infection.
- Use of catheters: People who require urinary catheters, such as those with spinal cord injuries or hospitalized patients, are at an increased risk of UTIs due to the introduction of bacteria through the catheter.
- Weakened immune system: Individuals with weakened immune systems, such as those with diabetes, HIV/AIDS, or those undergoing chemotherapy, are more vulnerable to UTIs as their bodies struggle to fight off infections.
- Urinary retention: Incomplete emptying of the bladder can provide an environment for bacteria to grow and multiply, increasing the risk of UTIs. Conditions that can cause urinary retention include constipation, nerve damage, or an enlarged prostate in men.
Symptoms of UTIs
The symptoms of urinary tract infections can vary depending on whether the infection affects the lower or upper urinary tract. Symptoms of a lower UTI in the bladder or urethra include:
- Dysuria: Pain or burning sensation during urination, often described as a sharp or stinging pain.
- Increased frequency and urgency: The need to urinate more frequently than usual, even when the bladder is not full, accompanied by a sudden, strong urge to urinate.
- Hematuria: The presence of blood in the urine, which may cause the urine to appear pink, red, or brown.
- Cloudy or strong-smelling urine: UTIs can cause urine to become cloudy, murky, or unusually strong-smelling.
Upper urinary tract infections involving the kidneys (pyelonephritis) are more serious and can lead to complications if left untreated. Symptoms of pyelonephritis include:
- High fever: A temperature of 101°F (38.3°C) or higher, often accompanied by chills.
- Chills: Shivering or feeling cold, even when in a warm environment.
- Nausea and vomiting: Upset stomach and the need to vomit, which can cause dehydration if severe.
- Back and side pain: Pain in the side and back, usually located below the ribs and above the waist, often radiating to the lower abdomen and groin.
Parents and caretakers responsible for children and older adults will need to look for signs of a UTI, especially if the child or adult cannot communicate their symptoms. In children, symptoms may include:
- Irritability and fussiness
- Poor appetite
- Unexplained fever
- Vomiting or diarrhea
- Unusual odors in the diaper
- Pain or burning during urination (for toilet-trained children)
In older adults, UTI symptoms may be less specific and can include:
- Confusion or delirium
- Fatigue or weakness
- Loss of appetite
- Incontinence or increased urgency
- Low-grade fever
Diagnosis of UTIs
To accurately diagnose a urinary tract infection, healthcare professionals will typically consider the patient’s medical history, conduct a physical examination, and perform laboratory tests. In some cases, imaging tests or a cystoscopy may be necessary.
Urine tests are essential in diagnosing UTIs, as they can detect the presence of bacteria, white blood cells, and other signs of infection. The two main types of urine tests used in UTI diagnosis are:
- Urinalysis: With a urinalysis, a urine sample is analyzed using several laboratory methods. It’s also examined under a microscope to check for the presence of white blood cells, red blood cells, and bacteria. A urinalysis can provide preliminary information about whether an infection is present but does not identify the specific type of bacteria causing the UTI.
- Urine culture: During a urine culture, a urine sample is placed on a special growing media. Any bacteria that grow in the media can be identified and tested for the specific antibiotics that will kill them and the antibiotics that will not be effective against them.
Additional Imaging tests may be necessary if the person has recurrent UTIs, an abnormality in the urinary tract, or if the infection does not respond to initial treatment. The most common imaging tests for diagnosing UTIs include:
- Ultrasound: An ultrasound can help identify any abnormalities of the urinary tract, such as blockages or swelling, that could contribute to the infection.
- CT scan: A computed tomography (CT) scan can reveal structural abnormalities, kidney stones, or other issues that may lead to UTIs.
- MRI: Magnetic resonance imaging (MRI) may be used to get a more detailed view of the urinary system and any underlying issues.
- Cystoscopy: A cystoscopy, in which a thin, flexible tube with a light and camera (cystoscope) is inserted into the urethra to examine the bladder and urethra, is most often used for patients with recurrent UTIs, suspected bladder abnormalities, or those who do not respond to standard treatment.
UTI Treatment
Once a person has been diagnosed with a UTI, they can begin the appropriate treatment. Treatments aim to eliminate the infection and manage pain and other symptoms until the infection is resolved.
Antibiotics
Antibiotics are the primary treatment for UTIs, as they target and kill the bacteria causing the infection. The antibiotic choice and treatment duration depend on the type of bacteria and the results of the antibiotic testing of the urine culture.
Commonly prescribed antibiotics for UTIs include trimethoprim-sulfamethoxazole (Bactrim, Septra), nitrofurantoin (Macrobid), fosfomycin (Monurol), cephalexin (Keflex), and fluoroquinolones (such as ciprofloxacin or levofloxacin).
The length of antibiotic treatment varies depending on the severity and location of the infection. Lower UTIs usually require a 3–7 day course of antibiotics, while upper UTIs (pyelonephritis) may need a 7–14 day course or even intravenous (IV) antibiotics. It’s important to complete the course of antibiotics as prescribed to ensure the best results and prevent the bacteria from becoming resistant. Antibiotic resistance means that the antibiotic will no longer kill the bacteria and there may be fewer options to treat it if it returns.
Pain relief
Over-the-counter pain relievers, such as acetaminophen (Tylenol) or ibuprofen (Advil and Motrin), can help manage pain and reduce any fever associated with the UTI. Additionally, phenazopyridine (Azo) is a medication designed to alleviate urinary pain, burning, and urgency while the infection is treated.
Fluid intake and hydration
Drinking plenty of water can help flush out bacteria from the urinary tract and dilute the urine, making urination less painful. Patients with UTIs should aim to drink at least 8–10 glasses of water per day.
Preventing UTIs
Certain lifestyle changes can help prevent UTIs. Some of the most effective strategies include:
- Maintaining proper hygiene: Maintain good personal hygiene, including regular bathing and cleaning the genital area with mild, unscented soap. For women, wiping front to back can decrease the chance of bacteria getting into the urethra from the anal area.
- Practicing good voiding habits: Urinate regularly and avoid holding in urine for extended periods, as this can encourage bacterial growth in the bladder.
- Avoiding irritants: Steer clear of potential irritants, such as harsh soaps, bubble baths, and scented feminine hygiene products, which can increase the risk of UTIs.
- Consider supplementing with cranberry products: Some studies suggest that consuming cranberry juice or taking cranberry supplements may help prevent
Complications of UTIs
Urinary tract infections can lead to serious complications if left untreated or improperly managed. An untreated or inadequately treated UTI can spread from the bladder to the kidneys, leading to a more severe infection called pyelonephritis. Kidney infections can cause permanent kidney damage if not promptly treated.
In rare cases, the bacteria causing the UTI can enter the bloodstream, leading to a life-threatening infection called sepsis. Sepsis requires immediate medical attention and aggressive treatment to prevent organ failure and death.
Patients should seek immediate medical attention if they experience any of the following:
- Persistent or worsening symptoms: If UTI symptoms do not improve or worsen after 2–3 days of treatment, consult a healthcare provider, as this may indicate a more severe infection or an ineffective antibiotic.
- Signs of a kidney infection: High fever, chills, nausea, vomiting, and severe back or side pain may indicate a kidney infection. Prompt medical attention is crucial to prevent permanent kidney damage.
- Signs of sepsis: Rapid heartbeat, rapid breathing, confusion, dizziness, and a drop in blood pressure are possible signs of sepsis, which requires immediate medical attention and treatment. Don’t delay care if you experience these symptoms. Call 911 or go to an emergency room.
- Pregnant women with UTI symptoms: Pregnant women who suspect they have a UTI should consult a healthcare provider as soon as possible since UTIs during pregnancy can lead to complications for both the mother and the baby.
FAQs
Can UTIs be sexually transmitted?
UTIs are not sexually transmitted infections. However, sexual activity can introduce bacteria into the urethra, increasing the risk of infection, particularly in women. To minimize the risk of UTIs after sexual activity, both partners should practice good hygiene, and it is recommended to urinate before and after intercourse to help flush out any bacteria.
Can men get UTIs?
While UTIs are more common in women due to their shorter urethra, men can also develop urinary tract infections. Risk factors for UTIs in men include an enlarged prostate, urinary tract abnormalities, and the use of urinary catheters.
Can I treat a UTI without antibiotics?
Antibiotics are the primary treatment for UTIs, as they target and kill the bacteria causing the infection. While some mild UTIs may resolve on their own, using antibiotics ensures proper treatment and reduces the risk of complications. Self-treating with over-the-counter medications or home remedies may temporarily relieve symptoms but do not address the underlying infection.
Are UTIs contagious?
UTIs are not contagious and cannot be spread from person to person through casual contact or sharing personal items. However, practicing good hygiene helps prevent the spread of bacteria that could cause UTIs.
Can cranberry juice cure a UTI?
Cranberry juice and cranberry supplements are often recommended for UTI prevention due to their potential ability to prevent bacteria from adhering to the lining of the urinary tract. While cranberry products may help reduce the risk of UTIs, they are not a substitute for antibiotics and should not be used to treat an active infection.