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Urinary Tract Infection


A urinary tract infection is an infection of one or more structures of the urinary tract. Polyuria and dysuria are common symptoms.


Population at increased risk

People who have obstructed urinary tract conditions such as kidney-stone or with a history of having incomplete bladder emptying (spinal cord injury, bladder decompensation etc.) are at a higher risk of developing the UTI. Suppression of the immune system (HIV/AIDS patients or patients with diabetes), and use of immunosuppressant medications can also increase the risk of developing a UTI several-fold. Catherization and Hospital-admission increases the risk of all types of infection including UTI [3].

Women: Sexually active women, women who use diaphragm as a birth-control measure are at increased of developing UTI [5].

Men: Though men are less likely to develop UTI, an enlarged prostate can lead to incomplete bladder emptying making them prone to such infections.

Infants: In this group of patients, the bacteria can also gain entry to urinary tract through the bloodstream from other infected sites of the body.

Young Children: Children have difficulty in wiping or cleaning them after the bowel movement. Thus, poor hygiene is linked to increase in the frequency of UTI.

Clinical presentation

Musculoskeletal: There is a constant mild or moderate pain in the pelvic region of women. Among men, similar pain is observed in the rectal region.

Neurological: In patients with UTI most frequently suffer from confusion and drowsiness. In some patients, gait disturbance is also observed.

Urogenital: Some of the urogenital features of the UTI are dysuria, frequent urination, urinary urgency, and abdominal pain. There can be new incontinence or worsening of the pre-existing incontinence in patients with UTI.

  • Pain: Pelvic pain and rectal pain is observed in women and men suffering from UTI respectively. Treatment of UTI depends on the extent of the infection.[symptoma.com]
  • We report the case of a 58-year-old man presenting with chest pain who underwent percutaneous coronary intervention (PCI). The patient subsequently developed a fever over 38 C, pain on micturition, and cloudy urine 3 days following PCI.[ncbi.nlm.nih.gov]
  • This medicine only relieves pain and does not cure the infection. Prevention Changing personal hygiene habits can help prevent recurrent UTIs.[web.archive.org]
  • Enteric fever caused by Salmonella Typhi is a global public health problem.[ncbi.nlm.nih.gov]
  • Fever may be a component of urethritis-related syndromes (eg, Reiter syndrome, Behçet syndrome) but rarely is observed in acute cystitis.[emedicine.medscape.com]
  • Call right away if you have signs of a possible kidney infection, such as: Back or side pain Chills Fever Vomiting Also call if UTI symptoms come back shortly after you have been treated with antibiotics.[nlm.nih.gov]
  • […] with a history of neurogenic bladder due to insulin-dependent diabetes mellitus and renal failure who was admitted to the urology clinic of a university hospital in Kirsehir, Turkey, with the complaints of urinary tract infection (UTI) including fever, chills[ncbi.nlm.nih.gov]
  • Fevers, chills, and malaise may be noted in patients with cystitis, though these findings are associated more frequently with upper UTI (ie, pyelonephritis).[emedicine.medscape.com]
  • Call right away if you have signs of a possible kidney infection, such as: Back or side pain Chills Fever Vomiting Also call if UTI symptoms come back shortly after you have been treated with antibiotics.[nlm.nih.gov]
Recurrent Urinary Tract Infection
  • Raz R, Gennesin Y, Wasser J et al (2000) Recurrent urinary tract infections in postmenopausal women. Clin Infect Dis 30(1):152–156 PubMed CrossRef Google Scholar 8.[oadoi.org]
  • OBJECTIVE: To provide an update of the definition, epidemiology, clinical presentation, investigation, treatment, and prevention of recurrent urinary tract infections in women.[ncbi.nlm.nih.gov]
  • urinary tract infection (UTI) in children through meta-analysis of randomised controlled trials.[doi.org]
  • One month later, the patient presented again with fatigue, leukocytosis, and leukocyturia. Blood and urine culture results were consistent with Klebsiella pneumoniae.[ncbi.nlm.nih.gov]
  • […] urgency to urinate incontinence during day and/or night frequent urination painful or difficult urination discomfort above the pubic bone blood in the urine foul-smelling urine nausea and/or vomiting fever chills pain in the back or side below the ribs fatigue[childrenshospital.org]
  • The need to urinate at night Abnormal urine color (cloudy urine) Blood in the urine Strong or foul-smelling urine Other symptoms that may be associated with a urinary tract infection include: Pain during sex Penis pain Flank (side of the body) pain Fatigue[my.clevelandclinic.org]
  • Urgency to urinate Incontinence during day and/or night Frequent urination Painful or difficult urination Discomfort above the pubic bone Blood in the urine Foul-smelling urine Nausea and/or vomiting Fever Chills Pain in the back or side below the ribs Fatigue[stanfordchildrens.org]
  • […] feeling of having to urinate even though little or no urine actually comes out pain in the lower abdomen pain above the pubic bone (in women) a full feeling in the rectum (in men) bloody or foul-smelling urine mild fever a general feeling of shakiness and fatigue[sxu.edu]
Severe Clinical Course
  • It is assumed that UTI is complicated when there are risk factors for a severe clinical course or for secondary harms ( Box gif ppt ).[dx.doi.org]
  • It is assumed that UTI is complicated when there are risk factors for a severe clinical course or for secondary harms ( box ).[ncbi.nlm.nih.gov]
  • Although treatment with antibiotics administered intravenously improved the fever, laboratory findings, and right back pain, she had prolonged headaches, nausea, and vomiting.[ncbi.nlm.nih.gov]
  • The most commonly side effects were digestives (nausea) and insomnia. Some tendinopathy was reported.[dx.doi.org]
  • Nausea. Pelvic pain (especially in women). Types of UTI The symptoms you experience with a UTI depend on which part of your urinary tract is affected.[mercy.net]
Abdominal Pain
  • We report a case of a 15-year old boy who was referred to our clinic with complaints of abdominal pain, and an ultrasound report of "absent right kidney".[ncbi.nlm.nih.gov]
  • Serious side effects include fever, yellowing skin or eyes, easy bruising or bleeding, dark or bloody urine, change in the amount of urine, abdominal pain, vomiting, chills, unusual tiredness, shortness of breath, fast heartbeat, and seizures.[rxlist.com]
  • Some of the urinary tract infection (UTI) symptoms your child may experience include the following: Babies fever abdominal pain colic abdominal fullness foul-smelling urine poor growth weight loss or failure to gain weight irritability vomiting poor feeding[childrenshospital.org]
Suprapubic Pain
  • Presentation The presenting features of lower urinary tract infection include frequent urination or an urgent need to urinate, dysuria, suprapubic pain and turbid or foul smelling urine. Fever and non-specific lower back pain may be present.[doi.org]
  • The following factors have been established from clinical studies ( 7, 8 ): • Dysuria, pollakisuria, nycturia ( ) • Present or increased incontinence ( ) • Macrohematuria ( ) • Suprapubic pain ( ) • “Offensive” smell, turbid urine ( ) • Prior infections[dx.doi.org]
  • The abrupt onset of irritative voiding symptoms (eg, frequency, urgency, nocturia, dysuria) and suprapubic pain are clinically diagnostic. Most cases of bacterial cystitis occur by an ascending mechanism.[emedicine.com]
Lower Abdominal Pain
  • Recurrent chronic lower abdominal pain and urinary tract infection in a young person may be due to congenital renal abnormality. Evaluation of persistent urinary abnormalities in a child should include screening for congenital abnormalities.[ncbi.nlm.nih.gov]
  • In older children, common signs include burning or pain with urination, frequent or urgent urination, fever, lower abdominal pain, new or more frequent incontinence, side or back pain, or blood in the urine.[childrenshospitaloakland.org]
  • Signs and Symptoms Diagnosis Treatment The symptoms of UTI can include: Pain or burning with urination Lower abdominal pain or pressure The need to urinate frequently The urine may look cloudy or darker in color or it may appear bloody A fever, flank[ucsfhealth.org]
  • If your loved one is older, the main clues to watch out for are sudden changes in behavior and bladder control, especially if accompanied by lower abdominal pain or strong-smelling urine.[verywell.com]
Abdominal Tenderness
  • Examination findings may include the following: Fever Tachycardia Flank pain/costovertebral angle tenderness Abdominal tenderness in the suprapubic area Scrotal hematoma, hydrocele, masses, or tenderness Penile meatal discharge Prostatic tenderness Inguinal[emedicine.com]
Low Back Pain
  • At admission, she presented with a fever, chills, nausea, low back pain, and malaise, which were followed by progressive renal dysfunction. The initial presentation mimicked a urinary tract infection, which delayed the correct diagnosis.[ncbi.nlm.nih.gov]
  • Also call if your child has any of the following: bad-smelling, bloody, or discolored pee low back pain or belly pain (especially below the belly button) a fever of over 101 F (38.3 C) in children or 100.4 F (38 C) rectally in infants Call the doctor[kidshealth.org]
  • The symptoms of dysuria, urgency, hesitancy, polyuria, and incomplete voids may be accompanied by urinary incontinence, gross hematuria, and suprapubic or low back pain. Patients may demonstrate some suprapubic tenderness to palpation.[emedicine.medscape.com]
  • back pain or other aches Feeling “lousy” or tired UTI Signs Sediment (gritty particles) or mucus in the urine or cloudy urine Bad smelling urine (foul odor) Blood in urine (pink or red urine) Note : The appearance and smell of your urine may change because[sci-info-pages.com]
  • Acute confusion is a common symptom of physical illness in the older patient. In the majority, it is transient and resolves on treatment of precipitants.[ncbi.nlm.nih.gov]
  • Some older adults with a UTI also develop confusion. The tricky part Some of these UTI symptoms are similar to the symptoms of other conditions common in older people.[health.harvard.edu]
  • Pain or burning during urination Pressure in the lower pelvis Frequent need to urinate Cloudy urine Blood in the urine Foul smelling urine Other symptoms can include painful sexual intercourse, pain in the side and mental confusion.[parkview.com]
  • Fever, feeling sick in general, confused, tired, shaky or just out-of-it. If your doctor suspects you have an infection, they will ask you for a urine specimen which will be tested in a laboratory. Taking antibiotics for a prescribed amount of time.[margarettietz.org]
  • If an elderly patient comes to the hospital because they are confused and not feeling well, it's important that doctors rule out common problems (such as UTI) first, before they start treatment for other, less common problems, Shah said.[livescience.com]
  • Polyuria and dysuria are common symptoms.[symptoma.com]
  • Acute Urethritis Versus Cystitis The symptoms of acute urethritis overlap with those of cystitis, including acute dysuria and urinary hesitancy.[emedicine.medscape.com]
  • […] history of neurogenic bladder due to insulin-dependent diabetes mellitus and renal failure who was admitted to the urology clinic of a university hospital in Kirsehir, Turkey, with the complaints of urinary tract infection (UTI) including fever, chills, dysuria[ncbi.nlm.nih.gov]
Urinary Incontinence
  • The main factors associated with RUTI in postmenopausal women are vesical prolapse, cystocoele, post-voidal residue and urinary incontinence, all associated with a decrease in oestrogen. The use of oestrogens to prevent RUTI has been proposed.[ncbi.nlm.nih.gov]
  • These may include urinary incontinence and mental confusion (caused by the bacterial penetration of the blood-brain barrier ).[verywell.com]
  • incontinence or urinary catheter placement Kidney stones Prostate enlargement In young children, there can sometimes be a structural problem in the urinary tract that can lead to more frequent UTIs.[web.archive.org]
  • Burkhard, EAU Guidelines on Assessment and Nonsurgical Management of Urinary Incontinence, European Urology, (2018).[dx.doi.org]
Flank Pain
  • A 40-year-old female presented in severe sepsis and complaining of flank pain. Prompt bedside ultrasound demonstrated hydronephrosis, expediting definitive urologic treatment via percutaneous nephrostomy tube placement.[ncbi.nlm.nih.gov]
  • With that being said, if you develop signs of a kidney infection, including flank pain, nausea, or vomiting, you need to see a doctor immediately.[verywell.com]
  • The hallmark symptoms are fever and flank pain. However, nausea and generalized abdominal pain often dominate the clinical picture.[web.archive.org]
  • pain, nausea or vomiting accompanying any of these symptoms could signal that the infection has reached the kidneys, and you should seek immediate medical attention.[ucsfhealth.org]
Cloudy Urine
  • The patient subsequently developed a fever over 38 C, pain on micturition, and cloudy urine 3 days following PCI. Urine cultures were positive for Escherichia coli and Enterococcus faecalis, whereas blood cultures were negative.[ncbi.nlm.nih.gov]
  • Pain or burning during urination Pressure in the lower pelvis Frequent need to urinate Cloudy urine Blood in the urine Foul smelling urine Other symptoms can include painful sexual intercourse, pain in the side and mental confusion.[parkview.com]
  • Symptoms of UTIs include a burning sensation while urinating, frequent urination, painful urination, passing very little urine even when you have a strong urge to go, pain in the pelvic region or back, foul-smelling or cloudy urine, and fever or chills[stmaryhealthcare.org]
  • Symptoms include abdominal pain , a strong urge to urinate, burning pain with urination, and cloudy urine. Treatment for UTI includes taking medication.[goodrx.com]
  • We report the case of a 5-year-old girl who presented with hematuria and a urinary tract infection and on workup was found to have a large bladder mass. Transurethral resection and pathologic examination revealed the mass to be a ganglioneuroma.[ncbi.nlm.nih.gov]
  • Hematuria may be present but does not help differentiate pyelonephritis from cystitis. Urine culture reveals 10 5 CFU/mL in 80% to 95% of cases. Some patients, as discussed above, have lower colony counts.[web.archive.org]
  • INFANTS AND TODDLERS: fever, vomiting, abdominal pain, dysuria, hematuria.[clinicaladvisor.com]
  • […] urge to urinate (urinary urgency) The need to get up at night to urinate ( nocturia ) Inability to hold your urine (urinary incontinence) Passing frequent, small amounts of urine Foul-smelling urine Cloudy urine caused by pus ( pyuria ) Bloody urine ( hematuria[verywell.com]


Diagnosis of UTI

  • While the location of UTI can help to classify the type of infection, it is very difficult to determine the extent of infection just based on the symptoms.
  • In elderly, UTI may present only as urinary incontinence, without any other symptoms.
  • Urine dipstick test: This test shows the positive nitrate and/or leukocyte esterase indicating the probability of UTI [5].
  • A positive urine culture is the true diagnostic test for UTI. The urine culture must be performed in the setting of the clinical infection as asymptomatic bacteriuria is common and does not need any treatment [6].

These tests may be indicated in UTI:

  • Urine analysis: This test is performed to check the presence of bacteria by chemical tests such as the presence of nitrites in the urine.
  • Complete blood count (CBC) and blood culture are also done in some cases.
  • Clean catch” urine culture can be done to identify the bacteria and its sensitivity to the antibiotics for treatment.
  • Imaging: Sometimes CT scan for abdomen, kidney scan and ultrasound, and Intravenous pyelogram (IVP) may also be required to assess the extent of infection.
  • Probiotics and dietary manipulations in calcium oxalate nephrolithiasis: two sides of the same coin? Kidney Int. 78, 1063–1065 (2010). 91. Sidhu, H. et al.[doi.org]
  • Thus, asymptomatic bacteriuria was found in 23% of women with cystocele, 57% of patients with congenital urologic disease, 85% of patients with hydronephrosis and nephrolithiasis, and in nearly all patients in whom an indwelling retention catheter has[web.archive.org]
  • […] but not nitrite, or have neither pyuria nor nitrite in the urine.[ncbi.nlm.nih.gov]
  • Non-infectious causes of pyuria (sterile pyuria) are discussed below. The nitrite test is used to screen for significant bacteriuria.[web.archive.org]
  • Reduction of bacteriuria and pyuria after ingestion of cranberry juice. J Am Med Assoc 1994; 271 : 751–754.[dx.doi.org]


Treatment of UTI depends on the extent of the infection

Mild kidney infections: In mild cases, following an antibiotic regimen for 3 days (women) or 7 - 14 days (men) can benefit the patient. In patients who are pregnant or suffer from diabetes, one must take antibiotics for 7 - 14 days. Drinking plenty of water can help flush the bacteria out of the system.

Severe kidney infections: In severe infections, the patient may have to get admitted to the hospital to receive intravenous fluids and antibiotics for immediate relief. The chances of such visits increase if the patient is elderly; have kidney stones, cancer, diabetes, spinal cord injury or other medical problems.

Recurrent bladder infections: Women must take antibiotics after the sexual contact and clean the pubic region with water. They can also take a single daily dose of an antibiotic to prevent infections.

Chronic UTI: In these cases, UTI persists even after taking antibiotics; such patients must take stronger antibiotics to combat the menace of UTI [7]. Surgery is advised if the infection has affected the anatomy of the excretory system.

Antibiotics that are frequently used to manage UTI are as follows [9]:


Most of the infections of the urinary tract can be treated successfully. The symptoms of UTI generally resolve with 24 to 48 hours after the initiation of the treatment. For severe infections, relief can come only after 7 days of treatment.


Though urine is generally sterile, when the infection begins, it starts at the opening of the urethra (the place from where the urine leaves the body) and moves upwards in the urinary tract. In 90% of the cases, the culprit of the uncomplicated infection is a type of bacteria called Escherichia coli, which normally lives in the colon and around the anus [2].

These bacteria can easily move around the anus and urethra. The most common causes of UTI are poor hygiene and sexual intercourse. Emptying of the bladder can help flush out the bacteria from the urethra. However, some bacteria can travel up the urethra to the bladder and grow, causing the infection. When the infection spreads further, these bacteria can even reach the kidney, which is a very serious condition, if not treated promptly.

Other species that cause UTI include Klebsiella, Proteus mirabilis, Enterococcus and Staphylococcus saprophyticus.


Though UTI is more common in adults than in children, the latter is more likely to suffer from its serious form and often get ignored. It is estimated that about 1-2% of the children suffer from UTI.

These infections are more common in women and girls younger than 50 years than their male counterparts, probably due to the anatomic differences between the genders. It is estimated that about 40% women and 12% men have suffered from UTI at least once in their life-time [1].

Sex distribution
Age distribution


The following stages can explain the pathogenesis of UTI in humans:

  • Colonization: Bacteria colonize in the urethral region of the urinary system. In the absence of proper hygiene, they continue to grow and ascend into the bladder.
  • Uroepithelium penetration: Bladder forms the safe haven for the multiplication of the bacteria. After the penetration of the bacteria, they rapidly replicate and may also form a biofilm.
  • Ascension: Once there is sufficient colonization and penetration of bacteria, they may ascend the ureters towards the kidney. Fimbria present in this region helps the bacteria to ascend. The bacterial toxins also cause reverse peristalsis in this region, inhibiting the flow of urine.
  • Pyelonephritis: When the bacteria reach the renal parenchyma of the kidney, they cause an inflammatory response called pyelonephritis. 
  • Acute kidney injury (AKI): If the treatment is not initiated, the bacteria can reach the renal tubules and may cause interstitial nephritis causing AKI.


UTI can be prevented. The following steps can reduce the risk of UTI significantly.

  • Drinking plenty of water or liquids ensure frequent urination, preventing the colonization of the bacteria in the bladder.
  • Wiping from front to back after urinating bowel movement can prevent the easy passage of the bacteria to the urinary system [10].
  • Emptying the bladder immediately after the intercourse and drinking a glass of water help to flush out of bacteria.

Summing up, though UTI is a common disease affecting all the segments of the population, it can be successfully managed and prevented by making people aware of the clinical complications. UTI can also be prevented by incorporating proper hygiene in their daily routine.


Anatomy of the excretory system

Kidneys are small organs that lie on either side of the spine. Apart from removing the waste and excess water from the body, kidneys also play an important role in the regulation of the blood-pressure. These organs are extremely sensitive to the changes in the blood-glucose levels; hence both diabetes and hypertension can adversely affect the working of the kidneys.

There are two ureters that drain the urine from each kidney to the urinary bladder. The bladder stores the urine and when a certain level of urine is collected, it voluntarily contracts to expel the urine.

Urethra connects the bladder to the outside of the body. Infection that involves the kidneys, ureters, urinary bladder and urethra (or excretory system) is called the Urinary Tract Infection (UTI). Any of the parts of this system can be infected and the further up the infection, the greater is the chance of infection to become serious.

Types of infection

  • Pyelonephritis: Infection of the upper excretory system namely, kidneys and ureters are called pyelonephritis. It leads to serious symptoms such as fever, chills, nausea and vomiting.
  • UrethritisInfection of the urethra.
  • CystitisInfection of the bladder.

Patient Information

A urinary tract infection (UTI) is an infection of a part of the urinary tract.

Though there are no specific signs and symptoms of UTI, but when they manifests they may show the following features:

The trouble during urination: There is a persistent and strong urge to urinate. While passing the urine, there is a burning sensation. The urine appears cloudy and sometimes it appears red, pink or cola-colored due to presence of blood.

Frequency of frination: The patient passes small quantity of urine frequently. In fact, the patient may be the distressed with the number of visits to the washroom.

Pain: Pelvic pain and rectal pain is observed in women and men suffering from UTI respectively.

Treatment of UTI depends on the extent of the infection.



  1. Foxman B. The epidemiology of urinary tract infection. Nat Rev Urol. Dec 2010;7(12):653-60
  2. Dalal S, Nicolle L, Marrs CF, Zhang L, Harding G, Foxman B. Long-term Escherichia coli asymptomatic bacteriuria among women with diabetes mellitus. Clin Infect Dis. Aug 15 2009;49(4):491-7.
  3. van der Starre WE, van Nieuwkoop C, Paltansing S, et al. Risk factors for fluoroquinolone-resistant Escherichia coli in adults with community-onset febrile urinary tract infection. J Antimicrob Chemother. Mar 2011;66(3):650-6.
  4. Hooton TM, Roberts PL, Cox ME, Stapleton AE. Voided midstream urine culture and acute cystitis in premenopausal women. N Engl J Med. Nov 14 2013;369(20):1883-91.
  5. Little P, Turner S, Rumsby K, Warner G, Moore M, Lowes JA, et al. Dipsticks and diagnostic algorithms in urinary tract infection: development and validation, randomised trial, economic analysis, observational cohort and qualitative study. Health Technol Assess. Mar 2009;13(19):iii-iv, ix-xi, 1-73.
  6. Lane DR, Takhar SS. Diagnosis and management of urinary tract infection and pyelonephritis. Emerg Med Clin North Am. Aug 2011;29(3):539-52
  7. Olson RP, Harrell LJ, Kaye KS. Antibiotic resistance in urinary isolates of Escherichia coli from college women with urinary tract infections. Antimicrob Agents Chemother. Mar 2009;53(3):1285-
  8. Wagenlehner FM, Schmiemann G, Hoyme U, Fünfstück R, Hummers-Pradier E, Kaase M, et al. [National S3 guideline on uncomplicated urinary tract infection: recommendations for treatment and management of uncomplicated community-acquired bacterial urinary tract infections in adult patients].Urologe A. Feb 2011;50(2):153-69.
  9. Cunha BA. Antibiotic Essentials. 7th ed. Royal Oak, Mich: Physicians Press.; 2008.
  10. Jepson RG, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. Jan 23 2008;CD001321.

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Last updated: 2019-07-11 20:45