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Urinary Tract Infection (UTI)


Urinary Tract Infection occurs when a pathogen (microorganism causing disease) enters and grows in your urinary tract, which includes a pair of kidneys and ureters (tubes that carry urine from kidneys to the bladder), a urinary bladder, and a urethra(a small box that carries urine from bladder to outside of the body). The urinary system is responsible for cleaning and filtering the blood and producing urine as a waste product. The urinary tract infection results in the appearance of the symptoms, which may include burning sensation when you pee, increased frequency of urine, tummy discomfort, pain in the flanks, fever, etc.

Urinary tract infections are prevalent. Females are affected more often than males. Antibiotics are used to treat the disease. You can also reduce your chances of getting an infection by following some lifestyle changes.


Usually, your body keeps the pathogens away from your urinary system, but sometimes these pathogens evade the defense mechanism and cause disease. They mainly infect the lower urinary tract, including the urinary bladder and urethra; however, they may also infect the upper urinary tract, including kidneys.

The most common bacteria causing a UTI is E. coli, with the lesser common organisms including staphylococcus, klebsiella, pseudomonas, viruses, and fungi. These pathogens can enter the body via three routes: the ascending spread through the urethra, blood, or the area around the anus.


Urethritis: If a urethra is affected, it results in urethritis. It may cause the symptoms like discharge and burning pee

Cystitis: When the urinary bladder is affected, it is called cystitis. It is more common and causes lower tummy discomfort, increased urine frequency, and blood in the urine.

Acute Pyelonephritis: Infection may start from the urethra and bladder and travel to one or both kidneys, causing pyelonephritis. It causes fever with shaking, chills, nausea, vomiting, and flanks. It requires prompt medical attention.

Risk Factors

The following risk factors may increase your chances of getting a UTI:

Gender: Women are more prone to UTI than men because of the short distance between the anus and urethra. The use of certain contraceptives like diaphragm and spermicides also increases the risk of menopause. Decreased estrogen hormone levels after menopause may lead to reduced levels of protective organisms in the vagina and vaginal atrophy, increasing the chances of UTI. In older males, the prostate gland enlarges and obstructs the urine outflow, increasing their risk of getting a UTI. The urinary bladder and urethra can also be co-infected with the prostate gland.

Sexual Activity: Sexually active women are more prone to UTIs.

Urinary Catheters: You may have an increased risk of UTI if a catheter is placed in your urinary tract due to immobility, recent surgery, or neurological disease. A urinary catheter is a flexible tube used to empty the bladder and collect urine in a urine bag.

Structural Abnormalities in the Urinary Tract: Sometimes, there is a structural abnormality of the urinary tract, resulting in urine accumulation resulting in recurrent UTIs. These may include extra valves, small kidneys, and a tortuous course of ureters in children, while stones, constipation, and enlarged prostate are more common in adults.

Weakened Immune System: a weak immune system due to diabetes or cancer medications (chemotherapy) can also increase the risk of getting a UTI.

Pregnancy: the hormonal changes in pregnancy leads to specific urinary tract changes that make you more prone to a UTI. Moreover, the pregnant uterus puts pressure on the bladder that hinders the complete emptying of the bladder, predisposing it to infection.

Other: Other risk factors may include recent urinary tract instrumentation, recent exposure to antibiotics, recurrent infections, advanced age.

Signs And Symptoms

You may have the following signs and symptoms if you suffer from a UTI.

  • Burning sensation during pee(dysuria).
  • Increased frequency and urge to pee.
  • Urine that may be cloudy, bloody, or smelly.
  • Discomfort or pain in the lower tummy.
  • If kidneys are affected (acute pyelonephritis), you may have fever, chills, nausea, vomiting, and flank or back pain.
  • Children with UTI may have fever, irritability, improper food intake, bedwetting.
  • Older people may appear confused and agitated with or without the other symptoms.


Usually, diagnosis of an uncomplicated UTI is made based on signs and symptoms. However, your doctor may ask you to undergo a few tests if the diagnosis is unclear.

Urinalysis: The doctor may ask you to submit a sample of clean urine which will be checked in the lab for urinary nitrites, white blood cells (leukocytes), leukocyte esterase, and red blood cells.

Urine Culture: This test may be ordered in un-resolving cases. In this test, the causative organism is grown in the lab, and its susceptibility to antibiotics is assessed.

Imaging Studies:  If you have recurrent UTIs, a doctor may advise the imaging studies like Ultrasound, CT scan, or MRI to check for structural abnormalities and stones.

Cystoscopy: In this test, a flexible tube with the camera is inserted in your urethra to view the inside of your bladder. This test is usually not indicated unless the case is complicated.

Differential Diagnosis

Vaginitis/Cervicitis: In females, infection of the vagina(vaginitis) or cervix (cervicitis) may sometimes be confused with a UTI.

Prostatitis: In males, prostate gland infection may be confused as UTI.

Other: sometimes, treatment with certain medications or radiation also results in symptoms similar to a UTI.


Following antibiotics are usually used to treat urinary tract infections. The dose and duration of the treatment will depend on your symptoms and the doctor’s decision.

  • Trimethoprim/sulfamethoxazole.
  • Nitrofurantoin.
  • Fosfomycin.
  • Fluoroquinolones (ciprofloxacin, levofloxacin) may be used as second-line treatment.
  • Cephalosporins(cephalexin) can also be used as a second-line treatment.


Usually, a shorter course of antibiotics is prescribed for uncomplicated UTIs, healed within 3-6 days. For complicated UTIs, the treatment may take longer.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on June 02, 2023.



Bladder Infection (Urinary Tract Infection—UTI) in Adults - NIDDK (

Urinary Tract Infection | Antibiotic Use | CDC,a%20bladder%20infection%20(cystitis).

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