Urinary tract obstruction can be induced by a myriad of conditions and is defined as a renal disease that causes hydronephrosis and leads to significant changes in normal kidney function [1] [2] [3] [4]. Narrowing or complete obstruction of the ureteropelvic or ureterovesical junctions, ureterocele, phimosis, and the presence of posterior urethral valves are common causes of congenital urinary tract obstruction, whereas nephrolithiasis, urinary tract infections (UTIs), benign prostatic hyperplasia (BPH), malignant tumors (both primary and metastatic), diabetic neuropathy, trauma, and use of several drugs (anticholinergics and alpha-adrenergic antagonists) are important acquired etiologies [1] [2] [4] [5] [6]. Depending on the degree of obstruction (unilateral vs. bilateral) and the rate at which hydronephrosis develops, symptoms are either abrupt or slowly progressive. In the acute setting, a sudden onset of sharp and often severe abdominal pain (known as renal colic) is the hallmark of urinary tract obstruction and is often accompanied by diminished urine output (ranging from oliguria to anuria) in complete obstruction [5] [6]. Pain might project into the genitalia if the lower urinary tract is the site of obstruction [6]. In slowly progressive forms, pain may be mild or even absent, while dysuria, nocturia, increased frequency and urgency, as well as a sensation of incomplete bladder emptying, are often reported [2] [6].

Urinary tract obstruction is a known risk factor for the development of both acute and chronic kidney disease, especially in children [4], which may have devastating long-term consequences in the absence of an early diagnosis. For this reason, physicians must conduct a thorough clinical workup, starting with a detailed patient history that will assess the presenting signs and symptoms and reveal preexisting disorders or events that might have caused obstruction [2]. In addition, a meticulous physical examination, with an emphasis on abdominal and genital inspection, palpation and percussion, is necessary to raise valid suspicion [2]. Urinalysis is one of the first laboratory studies that can be performed, and often shows hematuria and bacteriuria [5]. In addition, a full laboratory workup comprised of serum electrolytes, a complete blood count (CBC) and renal function tests must be carried out. Serum creatinine and blood urea nitrogen (BUN) are both high in acute obstruction, in which case imaging studies should be employed to identify the cause. If obstruction at the level of the urethra is suspected, either cystourethroscopy or voiding cystourethrography is recommended, whereas abdominal ultrasonography and computed tomography (CT) are used if hydronephrosis or ureteral obstruction might be present [5] [6]. If ultrasound and CT are not conclusive, urography or pyelography (anterograde or retrograde) is indicated [5] [6]. Several biochemical markers have been proposed as potentially useful indicators of obstructive uropathy and its severity (kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin, or KIM-1 and NGAL, but also several other), although further studies are required to solidify their place in general practice [4].

The treatment of UTO depends on the cause and severity of the obstruction. In some cases, medications may be used to relieve symptoms or treat underlying conditions. Surgical intervention may be necessary to remove obstructions such as kidney stones or tumors. In cases of severe obstruction, procedures like catheterization or stenting may be required to restore urine flow.

The prognosis for UTO varies based on the cause and duration of the obstruction. If treated promptly, many patients recover fully without long-term complications. However, prolonged obstruction can lead to permanent kidney damage or failure, emphasizing the importance of early diagnosis and treatment.

UTO can be caused by a variety of factors, including kidney stones, tumors, enlarged prostate, congenital abnormalities, and scar tissue from previous surgeries or infections. In some cases, the cause may be idiopathic, meaning it is unknown.

UTO can affect individuals of all ages, but certain causes are more prevalent in specific populations. For example, kidney stones are more common in adults, while congenital abnormalities are a frequent cause in children. Men are more likely to experience UTO due to prostate-related issues, especially as they age.

The pathophysiology of UTO involves the disruption of normal urine flow, leading to increased pressure in the urinary tract. This pressure can cause damage to the kidneys and other structures, resulting in impaired kidney function and potential kidney failure if left untreated.

Preventing UTO involves addressing risk factors and underlying conditions. Staying hydrated, maintaining a healthy diet, and managing chronic conditions such as diabetes and hypertension can reduce the risk of developing kidney stones and other causes of obstruction. Regular medical check-ups can help detect potential issues early.

Urinary Tract Obstruction is a condition characterized by the blockage of urine flow, which can lead to serious complications if not addressed promptly. Understanding the symptoms, causes, and treatment options is crucial for effective management and prevention of long-term damage.

If you suspect you have a urinary tract obstruction, it is important to seek medical evaluation. Symptoms such as difficulty urinating, pain, and recurrent infections should not be ignored. Early diagnosis and treatment can prevent complications and ensure better health outcomes.

1. Chevalier RL. Congenital Urinary Tract Obstruction: The Long View. Advances in chronic kidney disease. 2015;22(4):312-319.
2. Dmochowski RR. Bladder Outlet Obstruction: Etiology and Evaluation. Reviews in Urology. 2005;7(Suppl 6):S3-S13.
3. Bascands J-L, Schanstra JP. Obstructive nephropathy: insights from genetically engineered animals. Kidney International. 2005;68(3):925-937.
4. Wasilewska A, Taranta-Janusz K, Dębek W, Zoch-Zwierz W, Kuroczycka-Saniutycz E. KIM-1 and NGAL: new markers of obstructive nephropathy. Pediatr Nephrol. 2011;26(4):579-586.
5. Kasper DL, Fauci AS, Hauser SL, Longo DL, Jameson J, Loscalzo J. eds. Harrison's Principles of Internal Medicine, 19e. New York, NY: McGraw-Hill; 2016.
6. Porter RS, Kaplan JL. Merck Manual of Diagnosis and Therapy. 19th Edition. Merck Sharp & Dohme Corp. Whitehouse Station, N.J; 2011.