A Urinary Tract Infection, or UTI as it is more commonly known, is an infection caused by the colonization and growth of microorganisms at any point of the urinary tract. The urinary tract is a closed system that modulates the emission and excretion of urine from the kidneys to the bladder and, ultimately, out of the body via the urethra.
Under normal circumstances, the entire urinary tract is a sterile environment, with the sole exception of the exterior urethra. There are several mechanisms through which the body maintains sterility of the urinary tract; however, when harmful microorganisms manage to travel up the urethra to the bladder or even the kidneys, a UTI develops.
The vast majority of UTIs are caused by bacteria, with E. coli being responsible for over 80% of all infections. Much less often, fungi or parasites may be to blame for the appearance of a UTI.
A UTI may be classified based on which elements of the urinary tract are affected. In case that only the lower elements of the urinary tract, i.e., the urethra and bladder are involved, the infection is considered a Lower UTI. In cases in which the kidneys or ureters are involved, the infection is considered an Upper UTI.
The symptomatology of all UTIs is well established, and it presents as follows:
1. Burning During Urination
There are many different pathologies that can cause pain or burning sensations during urination, the most common of which is a Urinary Tract Infection. This clinical manifestation is called dysuria, and it occurs due to the fact that UTIs frequently cause significant inflammation of the urethra and bladder. Women, having a significantly shorter urinary tract, are much more susceptible to the effects of inflammation and frequently experience UTI-associated dysuria with greater intensity than men.
Many sexually transmitted diseases, such as gonorrhea and chlamydia, can cause a severe infection of the urinary tract that results in intense pain during urination. Although in most cases, the infections that cause painful urination are caused by abnormal bacterial growth, fungal and viral infections can also produce the same symptoms.
2. Increased Urination Frequency
One of the defining clinical manifestations of a Urinary Tract Infection is an increased frequency of urination. This symptom is often accompanied by increased urgency during urination and especially by decreased urinary volume. Patients also commonly report feeling as if they are unable to completely void their bladders, which causes significant discomfort.
Although more than a few chemical or natural substances act as powerful diuretics that increase the production of urine, increased urinary frequency is most often associated with obstruction and inflammation of the urinary vesicles.
It is important to note that regarding urination, a normal frequency can be subjective. Additionally, various factors, such as levels of physical activity, environmental temperature, and total fluid ingestion, can dramatically impact the number of times a person urinates per day. Having said that, the vast majority of people urinate anywhere between 4 to 10 times a day. Exceeding this range may be an indication of the presence of a urinary tract infection, especially in the presence of other symptoms.
3. Cloudy Urine
Cloudy urine is one of the most telling, and often ignored, signs of urinary tract infection. Urine, which is the result of a complex filtration process that takes place in the kidneys, is mainly composed of water and a small quantity of solutes which typically do not affect the transparency of the fluid.
When for some reason, such as having a UTI, the number of solutes present in the urine increases, it loses its transparency and begins to take on a cloudy appearance as if some solid material was dissolved in it.
Urine from a healthy individual may range from a pale yellow to a rich amber color. However, it remains transparent even in stronger concentrations levels and contains minute quantities of urate crystals and cells.
In the presence of a urinary tract infection, urine becomes contaminated with large quantities of bacteria and white blood cells and thus becomes opaque and cloudy. In cases of severe infection, pus is often detected in the urine.
4. Bloody Urine
The presence of blood in urine is known as hematuria.
In and of itself, hematuria is not a disease, but rather a symptom of another pathology or physical alteration of the urinary tract. For this reason, and depending on the underlying cause, bloody urine may or may not be accompanied by other symptoms.
It is important to note that bloody urine is not always a distinct red color and this causes confusion in many patients. Urine containing blood may appear a rosy tone or even a dark brown color.
In fact, in some cases, blood is present in such diluted quantities that urine appears a normal color despite having measurable quantities of erythrocytes, or red blood cells. In these cases, hematuria is usually discovered during a routine urinalysis or urine culture. This is known as microhematuria, and it is also clinically significant.
If blood clots are detected, or if the patient has difficulty urinating and develops a fever, begins to vomit, and experiences significant pain, emergency attention should be sought promptly as these signs indicate the presence of a more serious complication.
5. Foul Smelling Urine
Urine with a strong odor may be an indication of dehydration or, in some cases, a urinary tract infection. However, some foods and medicines have the potential to alter the odor of urine without signifying an underlying pathological cause.
Urine has a characteristic pungent odor, reminiscent of ammonia, which is caused by the presence of a chemical called urea. Thus, the higher the concentration of urea, the stronger the natural smell of the urine. In healthy individuals, strong-smelling urine likely indicates dehydration. Therefore, the first step for individuals whose urine has a stronger smell is to increase fluid intake.
If the patient is not dehydrated and their urine still has a malodorous quality, the most likely explanation is the presence of a urinary tract infection, in which case antibiotic treatment is the most appropriate treatment.
6. Discharge
Male and female patients may secrete discharge from their urethras during a urinary tract infection. UTI-related penile and vaginal discharge may be clear or cloudy if it contains pus. It is important to note that, in the case of female patients, UTIs produce a discharge that secretes out of the urethra and not the vaginal canal or cervix.
7. Abdominal Pain
A multitude of urological pathologies can generate abdominal pain, which often lead patients to hospital emergency rooms. Among these urological pathologies, we find renal colic, acute testicular pain, bladder retention, and urinary tract infection.
Since urinary tract infections comprise a wide variety of pathologies that have in common the progressive bacterial colonization of the tissues and pathways that extend from the urethral meatus to the renal cortex, they are often characterized by acute suprapubic pain in addition to dysuria, urgent urination and other common UTI symptoms.
Suprapubic pain is generally experienced along the lower abdominal cavity, and it may range from mild discomfort to intense acute pain.
Nevertheless, abdominal pain may also be a sign of a pathology affecting any of the organs located inside the pelvis such as those of the female reproductive apparatus, the prostate in men, the intestinal tract, etc. Therefore, abdominal pain by itself remains a complex and often insufficient diagnostic tool.
8. Lower Back Pain
When the infection spreads to the upper urinary tract and causes inflammation of the kidneys and ureters, patients almost invariably experience pain along the lumbar region. This pain may be unilateral or bilateral and can extend to the lower abdomen.
The characteristics of the pain as well as the urinary symptoms that accompany it can aid in the diagnosis of the infection.
9. Fever
When an upper urinary tract infection affects the kidneys, a febrile response can occur. A fever is a sort of alarm system that signals the entrance of toxins, viruses, and bacteria into our bodies. The result of the body’s febrile response is an immediate increase in body temperature above the normal values.
Fevers are the body’s primary method of hindering the survival of bacteria and viruses as well as a key component of immune apparatus activation. Fevers are, for the most part, entirely self-limiting, which means that they tend to end without external intervention.
Fevers, however, generate significant discomfort in patients and sometimes indicate the presence of serious underlying pathologies such as upper urinary tract infections.
In otherwise healthy adults, acute fevers that last less than 3 or 4 days are likely due to such infections. Fevers caused by other types of pathology tend to be chronic and recurrent.
10. Nausea
Renal infection often leads to the development of nausea. One of the primary roles of renal function in the body is the clearance of toxins and other harmful substances. Infected kidneys become highly inefficient at their job, and thus toxins accumulate in the body which may, on occasion, generate feelings of nausea.
Other gastrointestinal symptoms related to kidney involvement during a urinary tract infection include vomiting and diarrhea.
11. Fatigue
Another common symptom of upper urinary tract infections is the presence of asthenia or fatigue as it is more commonly called. Fatigue can be best described as a general feeling of weakness, drowsiness, or lassitude. Some patients report feeling a distinct lack of energy and motivation or the presence of physical exhaustion and tiredness.
When the kidneys are involved in the development of fatigue, the retention of uncleared toxic substances is responsible.
Other frequent causes of fatigue are cardiac disease and oncological disease, as well as the consumption of drugs, clinical depression, sleep disorders, etc.
12. Urethral Stricture
Urethral strictures are a frequent complication of untreated UTIs. A urethral stricture is a condition in which a segment of the urethra, the tube that carries urine out of the body, becomes narrower, making it difficult to urinate.
Urethral strictures affect men more often than women because of the extended length of the male urethra. However, female patients are not immune to them. A urethral stricture develops as a result of the repeated healing and fibrosis processes of the urethral mucosa and surrounding tissues.
Besides untreated and recurring urinary tract infection, other risk factors for developing a urethral strictures include traumatic, inflammatory events such as falls and pelvic fractures, medical negligence during a surgical intervention, etc.
Further complications of having a urethral stricture include urinary retention, higher risk for developing urinary calculi, higher risk of recurring UTIs, and urethral fistulas.
13. Sepsis
In extreme cases of severe infection, if treatment is ineffective and the infectious agents enter the patient’s bloodstream, sepsis may develop.
Sepsis is a syndrome of life-threatening, abnormal physiological responses associated with severe infection. These abnormalities are almost always secondary to an excessive immune response to the infection, which ends up damaging the patient’s own tissues and leading to multiple organ failure.
Sepsis is one of the most frequent causes of death from infection, despite advances in antibiotic medicine, Sepsis has a hospital mortality rate ranging between 30 and 60%.
» Conclusion
There are various pathogenic factors that determine the risk of getting a UTI, and these include alterations of the urinary flow, hormonal fluctuations, changes to the urethral or genital epithelium, hygienic habits, the presence of a urinary catheter, pregnancy, and diabetes. There is also a genetic predisposition factor involving the expression of ABO group antigens on the surface of epithelial cells, such that patients who have a family history of UTIs are significantly more at risk of developing recurring infections of the urinary tract.
When a female patient meets the criteria for the presence of uncomplicated urinary tract infection, it is not typically necessary to perform urine culture. Detecting pyuria is sufficient to initiate a single dose or short-term antibiotic treatment. There is evidence that short treatment is more effective for UTI.
In men, UTIs should be considered carefully because of the inherent risk of prostatic tissue invasion. The greatest risk factors in young men are homosexuality, intercourse with a woman that has an active UTI, and having uncircumcised phimosis.
References
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