What is Uncomplicated Urinary Tract Infections (UTI)?
An uncomplicated urinary tract infection (UTI) is a type of bladder infection caused by bacteria. This happens in people who have normal urinary tracts and other health conditions, like diabetes or pregnancy, or recent surgery related to the urinary tract, aren’t present. This type of UTI is also referred to as cystitis or a lower tract UTI.
The presence of bacteria or white blood cells in urine alone, without any symptoms, isn’t enough to diagnose a UTI. Symptoms of a UTI typically include needing to urinate frequently, feeling a strong need to go right away, discomfort in the lower belly, and a painful or burning feeling during urination. UTIs are quite common in women, but not often seen in men who are circumcised. When a UTI does happen in a circumcised man, it’s usually considered a complicated UTI.
While many uncomplicated UTIs on their own over time without any treatment, many people seek medical help to get relief from the symptoms. The goal of treatment is to prevent the infection from spreading up to the kidneys or developing into a more serious condition called pyelonephritis, which can damage the tiny structures in the kidneys and eventually lead to high blood pressure.
To diagnose a UTI, a healthcare professional would consider the person’s symptoms and examine a sample of their urine. The urine sample must be collected properly for an accurate test and result.
Complicated UTIs and frequent or repeated UTIs are discussed in separate articles. Please refer to the companion StatPearls articles titled “Complicated Urinary Tract Infections” and “Recurrent Urinary Tract Infections” for more information.
What Causes Uncomplicated Urinary Tract Infections (UTI)?
Urinary tract infections (UTIs) in women often occur when harmful bacteria move up from the rectal area to the urethra, the tube that carries pee out of the body. Women are more prone to UTIs than men due to their shorter urethra, which makes it easier for bacteria to reach the bladder. Bacteria that spread through the blood rarely cause simple UTIs.
The most common cause of UTIs is the bacterium Escherichia coli, followed by Klebsiella. Other bacteria including Proteus, Enterobacter, and Enterococcus can also be responsible.
One of the biggest factors that increase the risk of getting a UTI is using a urinary catheter. UTIs are also pretty common after kidney transplants, primarily due to immune system weakening drugs and a condition where urine flows back up to the kidney. Other factors that can contribute are the use of antibiotics leading to antibiotic-resistant bacteria and having diabetes.
There are also several other factors that can increase the risk of UTIs:
* Difficulty in fully emptying the bladder or abnormalities in the way the urinary tract works
* The use of antibiotics leading to antibiotic-resistant bacteria
* Cystocele, a condition where the bladder drops into the vagina
* Lack of enough water intake
* Diarrhea
* Having first UTI before turning 15
* Regular pelvic examinations
* Inability to empty the bladder completely
* Weak or suppressed immune system
* Irritable bowel syndrome
* Post-menopause
* Having a mother with a history of many UTIs
* New or several sexual partners
* Poor hygiene
* Pregnancy
* Engaging in sexual intercourse
* Kidney stones
Utilizing birth control methods like spermicides and diaphragms can also result in a UTI.
Risk Factors and Frequency for Uncomplicated Urinary Tract Infections (UTI)
- UTIs, or urinary tract infections, are more common in females than males, occurring about 4 times more frequently.
- In the United States, 40% of women will have a UTI at some point in their lives.
- Approximately 10% of women will experience a UTI every year.
- UTIs can reoccur; nearly half of those affected have a second infection within a year.
- For women, UTIs most commonly happen between the ages of 16 and 35.
Signs and Symptoms of Uncomplicated Urinary Tract Infections (UTI)
Uncomplicated urinary tract infections (UTIs) typically cause discomfort and pain during urination, frequent urination, difficulty starting urination, an urgent need to urinate and discomfort at the lower stomach. There might be bladder spasms and blood in the urine too. Generally, people with uncomplicated UTIs do not experience fever, nausea, vomiting, chills, or back pain. Those symptoms are often seen with kidney involvement or a condition called pyelonephritis. People with neurological disorders, such as multiple sclerosis, may experience unusual symptoms, like an abrupt worsening of their neurological symptoms.
Sometimes, the symptoms of an uncomplicated UTI might resemble those of a kidney infection or another serious infection. In such cases, it’s usually best to take a cautious approach and treat for potential upper urinary tract disease. It’s important to gather information about any prior antibiotic use and past UTIs during diagnosis.
Physical examination typically doesn’t show anything unusual in a patient with an uncomplicated UTI, though 10-20% of cases might show tenderness in the lower stomach area. Patients with frequent UTIs, unexplained incontinence, or suspected organ prolapse should undergo a pelvic exam. Diagnosis of a UTI includes assessing signs and symptoms, carrying out a urinalysis and confirming results with a urine culture. Be cautious with a diagnosis based only on urinalysis or culture results in patients without symptoms. If there aren’t any clinical signs or symptoms, it’s most likely not a UTI.
Symptoms such as smelly or cloudy urine are often linked to UTIs and bacteriuria. But those symptoms alone don’t confirm a UTI that requires antibiotic treatment, unless the patient exhibits other signs or symptoms. In these cases, drinking more fluids and reviewing any contributing factors in the diet or medication use may be necessary.
There are several factors that can cause unusual cloudiness and odor in urine, such as certain foods, pregnancy, hydration levels, liver or kidney failure, medications, sexually transmitted infections, vaginal infections, vitamins, and bladder dysfunction unrelated to infection.
- Amorphous phosphates
- Foods (including asparagus, Brussels sprouts, fish, garlic, onions, spices, sulfur-containing foods)
- Hormonal changes (e.g., pregnancy)
- Hydration status
- Liver failure
- Medications (like sulfonylurea)
- Renal failure
- Sexually transmitted infections
- Vaginal infections
- Vitamins
- Voiding dysfunction unrelated to infection
In older or frail patients, symptoms may involve changes in mental state or behavior such as feeling lethargic, disorganized speech, or altered perception. The most reliable indicators in older and/or frail patients include a change in mental status, abnormal urinalysis results (pyuria and bacteriuria), and painful urination. Additional symptoms may include frequent night-time urination, incontinence, or a general sense of feeling unwell with no specific urinary symptoms.
- Change in mental status
- Abnormal urinalysis (presence of pus and bacteria in urine)
- Painful urination
- Frequent night-time urination
- Incontinence
- A general feeling of being unwell with no specific symptoms
Patients with spinal cord injuries and paralysis might experience various symptoms, including severe high blood pressure and headaches (known as autonomic dysreflexia), chills, cloudy, smelly urine, fever, increased or a new presentation of muscle tightness, or unexplained fatigue.
- Autonomic dysreflexia (severe high blood pressure and headaches)
- Chills
- Cloudy, smelly urine
- Fever
- Increased or a new presentation of muscle tightness
- Unexplained fatigue
Patients with permanently placed urinary catheters or suprapubic tubes may experience unclear signs and symptoms such as increased white blood cell count and low-grade fever. Most patients with catheters will show pyuria (pus in urine) and high urinary bacterial colony counts. However, this isn’t an actual urinary tract infection and shouldn’t be treated as such unless there are systematic signs or symptoms like pain, bladder spasms, blood in urine, or other abnormal bladder activity.
Testing for Uncomplicated Urinary Tract Infections (UTI)
Correctly collecting a clean urine sample is vital when assessing one’s health. It’s important to wash your hands before getting a sample. The best way to do this is known as a “midstream voided clean catch.” This works best with non-obese men and women, assuming they follow the right steps. However, obese women might struggle to provide an uncontaminated sample. If too many skin cells end up in the sample, it might be necessary to use a urethral catheter to get a cleaner sample. This carries a minor risk of causing a urinary infection.
Men should clean the penis, start to urinate to clear out the urethra, then collect a midstream sample. Young children or patients with spinal cord injuries might need a more direct method. If a patient has a catheter in place, the right thing to do is to change the catheter, then take a sample from the new one. Never use a sample taken directly from a drainage bag. If the urine can’t be sent to lab straight away, refrigerate it, because if it’s left out, bacteria can grow and bias the test results.
It’s important not to rely solely on looking at the urine to diagnose a urinary tract infection (UTI). Even clear urine can be infected, and cloudy urine isn’t necessarily due to an infection. All urine should be tested using a dipstick, which can be done at the clinic or the bedside. This test can look at the acidity, presence of nitrites, white blood cells, and blood. Keep in mind these tests can suggest a UTI, but don’t rule it out if the results are negative.
Typically, urine is slightly acidic. Certain bacteria can make the urine more alkaline. The nitrite test is quite accurate, as nitrites only appear when bacteria are present. This conversion process takes time, so the first urine of the day is often best for testing. Nevertheless, not all bacteria convert nitrates to nitrites, particularly ones causing complex UTIs like Enterococcus, Pseudomonas, and Acinetobacter. The white blood cell test can indicate a UTI, but other infections or conditions can also cause white blood cells to appear in the urine.
Blood in the urine can also indicate a UTI as it often comes along with bacterial infections. In fact, if you have nitrites, white blood cells, and blood in the urine, this can be very suggestive of a UTI, especially if the patient is also experiencing frequent urination and pain whilst urinating. When these symptoms are present, many labs will perform a thorough analysis of the urine looking for bacteria, white blood cells and red blood cells.
Even though urine cultures are not always necessary in simple UTIs, they may still be recommended due to increasing drug resistance, and to tell apart repeated from relapsing infections. Cultures can guide treatment. All men, patients with diabetes, those with impaired immunity, and pregnant women should have their urine cultured. The traditional teaching is that bacterial urine infection is present when the culture grows more than 100,000 bacteria per milliliter (CFU/mL). However, recent studies and guidelines now suggest that patients with symptoms and a urine culture showing >1,000 CFU/mL should be diagnosed with a UTI, and even counts as low as 1,000 CFU/mL may be considered diagnostic in symptomatic patients.
While standard urine cultures may not be helpful initially, they can be valuable if the patient doesn’t improve with the first course of antibiotics. Hence, in many cases, it’s recommended all patients treated for a UTI have a urine culture available. Procedures like cystoscopy and urinary tract imaging usually aren’t required for uncomplicated UTIs but may aid in the cases of recurrent infections.
Treatment Options for Uncomplicated Urinary Tract Infections (UTI)
Asymptomatic bacteriuria, or bacteria in urine without symptoms, is common and usually doesn’t need treatment. Exceptions are pregnant women, people with weak immune systems, organ transplant recipients, or those who recently underwent a urinary surgery. Significant bacteriuria is treated before any urinary surgery.
Quick guide to treating Uncomplicated UTIs:
Antibiotic treatments can range from 3 days to 6 weeks. There is a high success rate using “mini-dose therapy,” – just 3 days of treatment.
Different areas have varied levels of E. coli resistance to common antibiotics. If resistance to any antibiotic exceeds 50%, another drug should be chosen.
First-line treatments for uncomplicated UTIs include nitrofurantoin, sulfamethoxazole/trimethoprim, fosfomycin, and first-generation cephalosporins. In some countries, pivmecillinam is also first-line therapy.
* Nitrofurantoin is often preferred for uncomplicated UTIs. However it only inhibits the growth and doesn’t kill bacteria and must be used for 5 to 7 days. It is effective mostly in lower urinary tract due to its low tissue penetration and is not used for potential kidney infection (pyelonephritis). It’s often recommended for long-term prevention in patients with recurring UTIs.
Sulfamethoxazole/trimethoprim for 3 days can be a good mini-dose therapy, but many areas have high resistance rates. It’s not recommended in patients with sulfa allergy or if local bacteria resistance exceeds 20%.
Fosfomycin is approved by FDA as a single-dose therapy for uncomplicated UTIs. It can be used when there’s significant resistance to other antibiotics.
* First-generation cephalosporins are good for a 3-day mini-dose therapy but shouldn’t be overused to avoid bacteria becoming resistant.
Fluoroquinolones have high resistance but are preferred for kidney infection (pyelonephritis) and prostate infection (prostatitis) due to their high tissue penetration levels. They should not be used together with nitrofurantoin and are not recommended for uncomplicated UTIs.
Pivmecillinam is the first-line therapy for uncomplicated UTIs in several countries but not in the US as it has poor tissue penetration.
Around 20% of women with UTIs and no symptoms will get better by themselves, especially if they drink more fluids.
Recurring UTIs are often treated by good personal hygiene, Vitamin C to make urine more acidic, precautions after sex, and protection antibiotics or antiseptics like nitrofurantoin.
Methenamine converted to formaldehyde in the bladder if the urinary pH is less than 5.5, and vitamin C is used to reduce the pH level. Cranberry and D-mannose can also help prevent recurring UTIs. In post-menopausal women, using estrogen vaginal cream twice weekly can be helpful.
Increased water intake is beneficial in women with low urine volumes. The prophylactic treatment period is usually 6 to 12 months but can be extended.
Infections that keep coming back with the same organism need to be checked for a source, like a kidney stone or a pouch in the bladder’s wall that is not emptying properly.
What else can Uncomplicated Urinary Tract Infections (UTI) be?
When a doctor is trying to diagnose a simple urinary tract infection (UTI), they need to consider other possibilities as well. These can include:
- Bladder stones
- More complex UTI
- Problems related to food or diet
- Herpes
- Reactions to certain medications
- An overactive bladder
- Pelvic infections
- Prostate inflammation or infection
- Kidney infection
- Frequent recurring UTIs
- Relapsing UTI
- A interrupted blood supply to the kidneys
- Kidney stones
- Sexually transmitted diseases
- Inflammation of the urethra
- Vaginal inflammation or infection
By considering these possibilities, the doctor can ensure that they’re making the correct diagnosis and providing the best possible treatment.
What to expect with Uncomplicated Urinary Tract Infections (UTI)
Most women with a urinary tract infection (UTI) recover very well. Symptoms usually improve in 2 to 4 days with antibiotics. However, about 30% of women will have another UTI within 6 months. Difficulties are often seen in older patients, those with serious health conditions, or those with kidney stones. Recurring infections are also linked to conditions like diabetes, cancer, undergoing chemotherapy, and long-term use of a urinary catheter. The risk of dying from an uncomplicated UTI is almost none.
Several factors can predict a challenging road to recovery. These include:
* Being older in age
* Having bladder stones
* Undergoing chemotherapy
* Having chronic diarrhea
* Diabetes (especially if not well managed)
* Incontinence (unable to control urination)
* Limited movement
* Severe obesity
* Kidney stones
* Nerve damage or spinal cord injury
* Pelvic organ sagging
* Poor general health
* History of overactive bladder
* Having cancer
* Previous radiation treatment
* Kidney failure
* Sickle cell anemia
* Using a urinary catheter
Although the risk of dying from a UTI is low, these infections can seriously affect your quality of life. Besides the discomforting symptoms, the overall cost of treatment can be high. Many people miss work or school because of it. In severe cases, a hospital stay may be needed.
Possible Complications When Diagnosed with Uncomplicated Urinary Tract Infections (UTI)
Urinary Tract Infections, commonly known as UTIs, can have various complications. These include:
- Long-term inflammation of the prostate (Chronic prostatitis)
- Severe kidney or bladder infections with gas formation (Emphysematous pyelonephritis and cystitis)
- Focal inflammation of the kidney (Focal renal nephronia)
- High blood pressure (Hypertension)
- Inability to control urine release (Incontinence)
- Continued symptoms affecting the lower urinary system (Persistent lower urinary tract symptoms)
- Abscess or pus-filled cavity in the prostate (Prostatic abscess)
- Inflammation of the kidneys (Pyelonephritis)
- Kidney abscesses (Renal abscess)
- Severe kidney damage (Renal failure)
- Large kidney stones (Staghorn urinary calculi)
Preventing Uncomplicated Urinary Tract Infections (UTI)
Once you’ve been diagnosed with a urinary tract infection (UTI), it’s essential to drink more fluids. It’s also crucial to take all of your medication as directed, even if you start to feel better. Don’t take antibiotics unless your doctor recommends them, as this can make bacteria more resistant, which may make future infections harder to treat.
It’s important to take steps to prevent UTIs, especially for women who are at a higher risk. Here are some helpful strategies:
* It’s a good idea to use the bathroom after sex, as this can help to clear out any bacteria that may have entered the bladder during the act.
* After going to the bathroom, make sure to wipe from front to back. This helps prevent bacteria from the anal area, potentially causing an infection in the bladder or surrounding areas.
* Drinking a good amount of water and maintaining a strong flow of urine can also help to prevent infections.
* It’s better to take showers rather than baths, which can introduce bacteria into the urinary tract.
* When taking a shower, use a gentle, fragrance-free liquid soap, like liquid baby soap or baby shampoo. Liquid soaps are generally cleaner than bar soaps, which can gather bacteria.
* Use a clean, soft cotton or microfiber cloth to apply the soap when you bathe, and it’s best to clean the vaginal area first to prevent spreading bacteria.
Some women who frequently get UTIs may find it helpful to take antibiotics as a preventative measure. Additionally, there are some home remedies that might help to reduce the severity and frequency of UTIs. Some people have found that drinking cranberry juice, taking D-mannose or methenamine, and using probiotics can be beneficial. However, it’s always best to consult with a healthcare provider before starting any new treatment regimen.
