Urinary tract infections are one of the most common types of infections and occur more frequently in women than men. These infections occur when bacteria enter the urinary tract, which can include the kidneys, bladder, and tubes that run between them.
What Causes an UTI?
Your urinary system includes your kidneys, ureters, bladder and urethra. All play a role in removing waste from your body. Your kidneys filter waste from your blood and regulate the concentrations of many substances. Tubes called ureters carry urine from your kidneys to the bladder, where it's stored until it exits your body through the urethra.
Bacterial cystitis/ UTI
UTIs typically occur when bacteria outside the body enter the urinary tract through the urethra and begin to multiply. Most cases of cystitis are caused by a type of Escherichia coli (E. coli) bacteria.
Bacterial bladder infections may occur in women as a result of sexual intercourse. But even sexually inactive girls and women are susceptible to lower urinary tract infections because the female genital area often harbors bacteria that can cause a urinary tract infection.
Some people are more likely than others to develop bladder infections or recurrent urinary tract infections. Women are one such group. A key reason is physical anatomy. Women have a shorter urethra, which cuts down on the distance bacteria must travel to reach the bladder.
Women at greatest risk of UTIs include those who:
Are sexually active. Sexual intercourse can result in bacteria being pushed into the urethra.
Use certain types of birth control. Women who use diaphragms are at increased risk of a UTI. Diaphragms that contain spermicidal agents further increase your risk.
Are pregnant. Hormonal changes during pregnancy may increase the risk of a bladder infection.
Have experienced menopause. Altered hormone levels in postmenopausal women are often associated with UTIs.
Other risk factors in both men and women include:
Interference with the flow of urine. This can occur in conditions such as a stone in the bladder or, in men, an enlarged prostate.
Changes in the immune system. This can happen with certain conditions, such as diabetes, HIV infection and cancer treatment. A depressed immune system increases the risk of bacterial and, in some cases, viral bladder infections.
Prolonged use of bladder catheters. These tubes may be needed in people with chronic illnesses or in older adults. Prolonged use can result in increased vulnerability to bacterial infections as well as bladder tissue damage.
In men without any predisposing health issues, cystitis is rare.
UTI signs and symptoms often include:
A strong, persistent urge to urinate
A burning sensation when urinating
Passing frequent, small amounts of urine
Blood in the urine (hematuria)
Passing cloudy or strong-smelling urine
A feeling of pressure in the lower abdomen
In young children, new episodes of accidental daytime wetting also may be a sign of a urinary tract infection (UTI). Nighttime bed-wetting on its own isn't likely to be associated with a UTI.
When to see a doctor
Seek immediate medical help if you have signs and symptoms common to a kidney infection, including:
Back or side pain
Fever and chills
Nausea and vomiting
If you develop urgent, frequent or painful urination that lasts for several hours or longer or if you notice blood in your urine, call your doctor. If you've been diagnosed with a UTI in the past and you develop symptoms that mimic a previous UTI, call your doctor.
Also call your doctor if urinary tract infection symptoms return after you've finished a course of antibiotics. You may need a different type of medication.
If your child starts having daytime wetting accidents, call your pediatrician.
In otherwise healthy men, cystitis is rare and should be investigated by your doctor.