A urinary tract infection (UTI) is an infection in any part of the urinary tract, which includes the urethra, kidneys, ureters, and bladder. Bladder infections are the most common form of UTI.
UTIs usually happen when harmful bacteria get into the urinary tract and start spreading. They are more common in females than in males, with about 10% of females reporting at least one UTI per year and 40–60% developing an infection at least once during their life.
The most common symptoms of a bladder infection include:
- burning during urination
- pain in the bladder that may feel like a persistent need to urinate, even immediately after using the bathroom
- only getting out a few drops when trying to urinate
- leaking urine
- cloudy or foul-smelling urine
- pelvic or stomach pain
Some pregnant women with UTIs do not get symptoms or only notice symptoms when the infection spreads to the kidneys.
A doctor or midwife may regularly test a pregnant woman’s urine for signs of a UTI. It is important to catch UTIs that occur during pregnancy early because they can affect the health of the fetus.
The symptoms of a bladder infection, which people may refer to as cystitis, are very similar to those of UTIs in other parts of the urinary tract. As a result, it may be difficult to tell which part of the urinary tract has an infection based on the symptoms alone.
An infection in the urethra may cause pain and burning when urinating and discharge from the urethra, but bladder pain is not a symptom.
An infection that has spread to the kidneys will cause the most severe symptoms. A person with a kidney infection may notice the same symptoms as those of a bladder infection, plus fever, chills, and back pain.
Treatment is usually the same for all types of UTI, except for kidney infections. Treating a kidney infection may require a person to stay in the hospital.
Kidney infections can cause serious health conditions, so anyone with these symptoms should seek treatment as early as possible.
UTIs occur when harmful bacteria enter the urinary tract and start spreading.
- Biological sex: Females have a shorter urethra than males, making it easier for bacteria to travel into the bladder or kidneys.
- Menopause: People may be more vulnerable to infections after menopause.
- Certain types of birth control: Using diaphragms and condoms with spermicide may make it easier for bacteria to get into the urinary tract.
- Unusual urethra shape: Genetic differences in the shape of the urethra may increase a person’s risk of getting a UTI.
- Urinary devices: Medical devices that affect the urinary system, such as catheters, may lead to UTIs.
- Sexual activity: Some females get UTIs when they have sexual intercourse, particularly if they start to have more frequent intercourse. Urinating after intercourse may reduce this risk.
- Chronic illness: Some illnesses that weaken the immune system, such as HIV and diabetes, make UTIs more likely.
To diagnose a UTI, a doctor will ask the person about their symptoms and carry out a physical examination. They are also likely to request a urine sample. If a certain number of white blood cells are present in the sample, they can indicate an infection.
The doctor will often send the urine sample to a laboratory where technicians will grow a culture and further analyze the bacteria to determine what antibiotics will work best.
As bacteria cause UTIs, antibiotics are the most effective treatment. It is important to take the right antibiotics at the correct dosage for a UTI, so a person should not reuse old prescriptions or self-medicate.
Sometimes, the first course of treatment does not work for a UTI. If this happens, a doctor may alter the dosage, change the antibiotics, or recommend intravenous (IV) antibiotics. People should call the doctor if their symptoms get worse after taking antibiotics or do not significantly improve within a few days.
Some people experience recurring UTIs. In these cases, a doctor may order further tests, such as an ultrasound scan or cystoscopy, to determine the root cause.
Treating a UTI at home has risks. Without treatment, the infection can spread. However, about 25–42% of UTIs in females resolve on their own.
Some home remedies may help people with recurring UTIs. These remedies include:
- Cranberry: A handful of studies suggest that cranberry may help flush out bacteria and prevent UTIs. One study found that a daily cranberry drink reduced the future need for antibiotics in women who had recently experienced a UTI. A small 2016 study that compared a cranberry extract with a placebo found that it helped prevent UTI recurrence.
- Probiotics: Some studies suggest that probiotics can improve vaginal flora and so reduce the number of pathogenic bacteria that could cause a UTI. Vaginal probiotics containing Lactobacillus crispatus, L. rhamnosus, and L. reuteri may help prevent UTIs from coming back.
- Estrogen: People who experience more UTIs after menopause may find that topical estrogen cream decreases their frequency.
Some at-home strategies can also reduce the discomfort of a UTI. They include:
- Hydration: Drinking plenty of fluids can help a person remain hydrated. They may also help a person urinate more frequently.
- Pain medication: Pain relievers, such as acetaminophen (Tylenol), may ease the pain of a UTI. However, these drugs will not treat the infection, so a person should still seek medical care.
- Avoiding sex: During a UTI, it is a good idea to avoid sexual intercourse, as this can introduce more bacteria into the urinary tract.
Home remedies do not work for everyone. A person with a UTI should consult their doctor before trying alternative strategies.
It is not always possible to prevent UTIs. However, certain lifestyle changes may help, such as:
- drinking enough water (about 2 liters per day)
- urinating when the urge arises and not putting it off
- urinating immediately after sex
- practicing good hygiene
- switching birth control method, for example, using condoms without spermicide
- drinking cranberry juice or taking a cranberry supplement
Sometimes, a UTI spreads to the kidneys or other areas of the body, or it does not respond to antibiotics. Some people need to take multiple antibiotics or receive IV treatment in the hospital.
People with a weakened immune system and those who delay treatment are more vulnerable to complications.
Although the body may sometimes fight off a UTI on its own, waiting for this to happen carries risks. UTIs can quickly spread, causing serious kidney infections.
A person should see a doctor for any symptoms of a UTI, particularly if they are pregnant or have an underlying health condition that affects their immune system.
A person with symptoms of a kidney infection should go to the emergency room for immediate medical care. The symptoms of a kidney infection include:
- feeling very sick
- pain in the middle of the back, especially when pushing on the area
UTIs can affect any part of the urinary tract, including the urethra, ureters, bladder, or in more serious cases, the kidneys. A bladder infection is a UTI that only affects the bladder.
It is not always possible to distinguish what UTI a person has because the symptoms of the different types can overlap. However, the treatment for most UTIs is the same. A doctor will typically prescribe antibiotics and recommend fluids.
The more promptly a person seeks treatment, the quicker they will generally get better. Early treatment also reduces the chances of a serious infection spreading to the kidneys or other areas of the body.