Symptoms and Causes
The urinary system is normally composed of two kidneys, two ureters,
a single urinary bladder and a single urethra. Urinary tract infection
(UTI) is a bacterial infection that affects any part of the urinary tract.
UTI is the second most common type of infection in the body.
What are the symptoms of a urinary tract infection?
The symptoms of urinary tract infections may vary with severity of
infection, age and location of infection in the tract.
Most Common Symptoms of urinary tract infection
Symptoms due to infection of the urinary bladder (Cystitis)
- Burning or pain during urination.
- Frequency of urination and persistent urge to urinate.
- Fever and malaise.
- Foul odor and cloudy urine.
Symptoms due to infection of upper urinary tract
- Lower abdomen discomfort.
- Frequent, painful urination with small amounts of urine.
- Usually low-grade fever without flank pain.
- Blood in urine.
- Upper back and flank pain.
- High grade fever with chills.
- Nausea, vomiting, weakness, fatigue and general ill-feeling.
- Mental changes or confusion in elderly people.
This is the most serious symptom of urinary tract infection as it implies
systemic involvement. Inadequate and delayed treatment can be life
Burning and frequent urination are common
signs of urinary tract infection.
What are the causes of recurrent urinary tract infection?
Important causes of frequent or recurrent urinary tract infections are:
- 1. Urinary tract obstruction:Various underlying causes which canlead to obstruction of urinary tract.
- 2. Female gender: Because of shorter urethra, women are more susceptible than men to UTI.
- 3. Intercourse:Women who are sexually active tend to have more urinary tract infections than women who aren’t sexually active.
- 4. Urinary stones: Kidney, ureter or bladder stone can block the flow of urine and increases risk for UTI.
- 5. Urinary catheterization:People with indwelling catheters have an increased risk of UTI.
- 6. Congenital urinary tract anomalies:Children with congenital
urinary tract anomalies such as vesicoureteral reflux (condition in
which urine moves backward from the bladder up the ureters) and
posterior urethral valve have an increased risk of UTI.
- 7. Benign prostatic hyperplasia:Men over 60 years are prone to
UTI because of an enlarged prostate (benign prostatic hyperplasia -
- 8. Suppressed immune systems: Patients with diabetes, HIV or
cancer are at higher risk for UTI.
9. Other causes:Narrowing of the urethra or ureters, tuberculosis of
the genito-urinary tract, neurogenic bladder or bladder diverticulum.
Can recurrent urinary tract infection cause damage to the
Recurrent lower urinary tract infection usually does not cause damage
to kidneys in adults.
UTI in adults can cause damage to the kidneys if predisposing factors
such as stone, blockage or narrowing of flow of urine and tuberculosis
of the genito-urinary tract are not corrected.
However, in young children, delayed or improper treatment of recurrent
urinary tract infection can cause irreversible damage to the growing
kidney especially in those with vesicoureteral reflux. This damage may
lead to reduction of kidney function and high blood pressure later in
life. So the problem of urinary tract infection is more serious in children
compared to adults.
Obstruction of urinary tract is
an important cause of recurrent UTI.
CHP. 18. Urinary Tract Infection 121.
Diagnosis of Urinary Tract Infection
Investigations are performed to establish diagnosis and severity of urinary
tract infection. In a person with complicated or recurrent urinary tract
infection different tests are performed to establish the presence of
predisposing or risk factors.
Basic Investigations for Urine Tract Infection
1. Urine test
Most important screening test for UTI is routine urinalysis. Early morning
urine sample is preferable for this test. In microscopic examination of
urine, presence of significant white blood cells is suggestive of UTI.
Presence of white blood cells in urine suggests inflammation of the urinary
tract but its absence does not exclude UTI.
Special urine dipstick (leukocyte esterase and nitrite) tests are useful
screening tests for UTI that can be done at the office or home. A positive
urine dipstick test suggests UTI and such patients need further evaluation.
The intensity of color change is proportional to the number of bacteria
in the urine.
UTI does not usually cause permanent damage to the kidneys in
adults in the absence of blockage of urine flow.
2. Urine culture and sensitivity test
The gold standard for the diagnosis of UTI is a urine culture test and it
should be done before starting antibiotic therapy. A urine culture is
recommended in complicated or resistant UTI and, in a few cases, for
the confirmation of the clinical diagnosis of urinary tract infection.
Urine culture test results are available after 48-72 hours. The significant
time delay between collection of sample and availability of the report is
a major drawback of this test. Urine culture identifies the specific
bacteria causing infection based on the nature of growth of the organism
and the number of colony forming units that grow in the Petri dish in the
laboratory. The urine culture result also includes the type of antibiotics
that the organism grown may be sensitive or resistant to. This guides
the doctor in the appropriate choice of antibiotic.
To avoid potential contamination of the urine sample, the patient is asked
first to clean the genital area and to collect midstream urine in a sterile
container. Other methods used for sample collection for urine culture
are supra-pubic aspiration, catheter-specimen urine and bag specimen
3. Blood tests
Blood tests usually performed in a patient with UTI include a complete
blood count (CBC), blood urea, serum creatinine, blood sugar and C
Investigations to Identify Predisposing or Risk Factors
If the infection does not respond to treatment or if there is repetition of
infections, further investigations, as mentioned below, are required to
detect underlying predisposing or risk factors:
- 1. Ultrasound and X-rays of the abdomen.
- 2. CT scan or MRI of the abdomen.
- 3. Voiding cystourethrogram - VCUG (Micturating cystourethrogram – MCU).
- 4. Intravenous urography (IVU).
- 5. Microscopic examination of urine for tuberculosis.
- 6. Cystoscopy - a procedure in which a urologist (kidney surgeon)
looks inside the bladder using a special instrument called a
- 7. Examination by a gynecologist.
- 8. Urodynamics.
- 9. Blood Cultures.
Urine culture and sensitivity is a valuable test
for the diagnosis and treatment of UTI.
Prevention and Treatment
CHP. 18. Urinary Tract Infection 123.
Prevention of Urinary Tract Infection
- 1. Drink plenty (3-4 liters) of fluids daily. Fluids dilute urine and help in
flushing bacteria out of the bladder and urinary tract.
- 2. Urinate every two to three hours. Do not postpone going to the bathroom. Holding urine in the bladder for a long period provides
opportunity for bacteria to grow.
- 3. Consume food containing vitamin C, ascorbic acid or cranberry juice
to make urine acidic eventually reducing bacterial growth.
- 4. Avoid constipation or treat it promptly.
- 5. Women and girls should wipe from front to back (not back to front)
after using the toilet. This habit prevents bacteria in the anal region
from spreading to the vagina and urethra.
- 6. Clean genital and anal areas before and after intercourse. Urinate
before and after intercourse and drink a full glass of water soon after
- 7. Women should wear only cotton undergarments, which allow air
circulation. Avoid tight-fitting pants and nylon underwear.
- 8. Recurrent urinary tract infection in women after sexual activity can
be effectively prevented by taking a single dose of an appropriate
antibiotic after sexual contact.
For successful treatment of UTI, it is essential
to identify underlying predisposing factors.
Treatment of Urinary Tract Infection
Drink plenty of water. A person who is very ill, dehydrated or unable to
take adequate oral fluids due to vomiting, will need hospitalization and
administration of IV fluids.
Take medications to reduce fever and pain. Use of heating pad reduces
pain. Avoid coffee, alcohol, smoking and spicy foods, all of which irritate
the bladder. Follow all preventive measures of urinary tract infection.
It is essential to drink plenty of water to
prevent and treat urinary tract infection.
CHP. 18. Urinary Tract Infection 125.
Treatment of lower urinary tract infection (cystitis, mild
In a healthy young female, short term antibiotics for three days is usually
enough. Some drugs need to be given for seven days to complete a
course. Occasionally, a single dose of an antibiotic such as Fosfomycin
can be used. Except for a previously healthy adult male who develops
a cystitis for the first time, adult males with UTI require 7 to 14 days of
antibiotics because of underlying structural abnormalities of the urinary
tract that make them prone to infection. Commonly used oral antibiotics
are nitrofurantoin, trimethoprim, cephalosporins, or fluoroquinolones.
The choice of antibiotic is best determined by the sensitivity and
resistance patterns of commonly used drugs in your locality.
Treatment of severe kidney infection (Pyelonephritis)
Patients with moderate-to-severe acute kidney infection, those with
severe symptoms or sick patients need hospitalization. Urine and blood
cultures are obtained before initiating therapy to identify causative
bacteria and proper selection of antibiotics. Patients are treated with
intravenous fluids and antibiotics for several days, followed by 10-14
days of oral antibiotics. If response to IV antibiotics is poor (marked
by persistent symptoms and fever, worsening kidney function) imaging
is indicated. Follow up urine tests are necessary to assess response to
Treatment of recurrent urinary tract infection
In patients with recurrent UTI, proper identification of the underlying
cause is essential. According to the underlying cause, specific medical
or surgical treatment is planned. These patients need follow-up, strict
adherence to preventive measures and long term preventive antibiotic
Treatment of severe kidney infections (pyelonephritis)
requires hospitalization and intravenous antibiotics.
126. Save Your Kidneys
When should a patient with UTI consult a doctor?
All children with UTI should be evaluated by a doctor. Adult patients
with UTI should immediately consult a doctor when there is:
- Decrease in urine volume or total absence of urine output.
- Persistent high fever, chills, back pain and cloudy urine or blood in
- No response to antibiotics after 2 to 3 days of treatment.
- Severe vomiting, severe weakness or fall of blood pressure.
- A single kidney.
- Previous history of stones.
Persistent high fever, chills, back pain, cloudy urine,
burning sensation need urgent attention.