An obstruction in the urinary system is a blockage that prevents urine from passing through its usual pathway (the urinary tract), which includes the kidneys, ureters, bladder, and urethra.

This condition is known as a urinary tract obstruction.

A blockage (obstruction) may cause an increase in pressure inside the urinary system and a decrease in the flow of urine. This can happen at any point along the urinary tract from the kidneys, which handle urine production.

Starting from the kidneys along the path to the urethra, which is the exit point for urine from the body.

• Hydronephrosis can sometimes be asymptomatic and only detected through routine imaging.
• Nephrostomy tubes can be temporary solutions to relieve urinary obstruction but may cause complications.
• Urinary stones are more common in individuals with chronic dehydration or specific dietary habits.
• Bladder catheterization is often the first diagnostic step for suspected urinary blockages.
• Endoscopic procedures can provide both diagnosis and treatment by removing obstructions directly.
• VCUG (voiding cystourethrography) is commonly used in children to diagnose urinary tract obstructions.

A urine blockage may happen all of a sudden, or it can build up gradually over days, weeks, or even months. It is possible for an obstruction to entirely shut off a section of the urinary tract or to merely partly do so.

There are cases in which just one kidney is damaged, but urine blockage may also influence both kidneys.

The majority of obstructions in children are caused by congenital conditions that disrupt the urinary system.

In children, structural abnormalities, such as birth defects such as valves in the inner rear part of the urethra (called posterior urethral valves), and other constrictions that restrict or clog the ureter or urethra occur.

Men, especially those over the age of 60, are also at a greater risk of being afflicted by this problem.

This is due to the fact that as men age, the prostate gland has a tendency to enlarge (a condition known as benign prostatic hyperplasia), which may obstruct the passage of urine.

As a result of the prevalence of BPH in men of advanced age, urine blockage is more prevalent in males.

Other frequent causes of blockage include strictures of the ureter or urethra, which may occur as a result of radiation treatment, surgery, or other operations performed on the urinary system.

Strictures are narrows produced by scar tissue.

Total blockage and partial obstruction sometimes produce the same kinds of difficulties.

But, obviously, complete obstruction often results in more severe manifestations of these issues, notably kidney impairment.

It’s possible for there to be a total blockage or only a partial one, and for it to come on suddenly (acutely) or gradually over time (chronically).

The factors that account for the majority of cases are:

A clog may cause damage to the kidneys, kidney stones, and infection in the kidneys.

Symptoms may include soreness on the side, a reduction or increase in the amount of urine that is passed, as well as the need to urinate throughout the night.

Total blockage may also occur due to kidney stone position or swelling because of infection.

During testing the urine blockages, procedures such as inserting a urethral catheter, inserting a viewing tube into the urethra, and imaging studies may be performed. The treatment may consist of both treating the underlying cause of the obstruction and making efforts to clear the obstruction itself.

The following problems could be found:

Hydronephrosis is the medical term for a swollen kidney. The kidney becomes enlarged and swollen in this condition, resulting from restriction of the normal flow of urine. 

Under normal circumstances, the kidneys release urine at a very modest rate of pressure.

If the flow of urine is blocked, urine will back up behind the site of obstruction. 

Eventually, the urine will reach the tiny tubes of the kidney and its collecting region (renal pelvis), causing the kidney to expand (distend) and increasing the pressure that is placed on its internal structures.

Urine accumulates in the kidney’s tiny tubes and the central collecting region as it is forced to flow backwards behind the blockage (renal pelvis).

This situation of the kidney is also known as a distended kidney. The increased pressure that is caused by the urine blockage may, in the long run, cause damage to the kidney, which may finally result in the kidney losing its function.

It is possible to develop hydronephrosis in both kidneys during pregnancy due to the fact that the expanding uterus puts pressure on the ureters.

Urinary calculi, often known as stones, are more prone to develop when the flow of urine is restricted.

When the flow of urine is impeded, it increases the risk of developing an infection. This is because germs that enter the urinary system are not washed out as effectively.

It is possible for renal failure to develop if both of the kidneys are blocked.

 Scar tissue may then replace the normal muscle tissue in the walls of the ureter, which may subsequently result in irreversible damage to the ureter.

The source, location, and length of time of the blockage all have a role in determining the symptoms.

In most cases, pain is experienced because the blockage starts suddenly and rapidly expands the bladder, ureter, and/or kidney.

Renal colic is a condition that may arise if the kidney is enlarged. 

On the back side of the body, when affected by renal colic, the terrible pain that occurs between the ribcage and the hip might be described as coming and going every few minutes.

There is a possibility that the discomfort may spread to the testis or the vaginal region. It is possible for people to experience nausea and vomiting.

The volume of urine that individuals pass even when they have one ureter blocked does not change.

If there is a blockage that affects the ureters from both kidneys or if there is a blockage that affects the urethra, then urination may cease completely or become significantly reduced.

Pain, pressure, and an enlarged bladder are symptoms that may be brought on by an obstruction of the urethra or the bladder outlet.

There is a possibility that obstructive hydronephrosis might be the source of a variety of gastrointestinal tract symptoms, including nausea, vomiting, and stomach discomfort.

Occasionally, a kidney stone can momentarily obstruct the ureter, which results in discomfort that comes and goes throughout the day.

People who have urinary tract infections (also known as UTIs) could have blood or pus in their urine, along with a fever and pain in the region of their kidneys or bladder.

It is essential to get a prompt diagnosis since most instances of blockage are treatable and because delaying treatment may cause renal damage that cannot be reversed.

The symptoms that a patient is experiencing, such as renal colic, signs of bladder distention, or a reduction in the amount of urine, might lead doctors to assume that the patient has an obstruction. 

Rarely, a distended kidney may be felt in the flank, and when it can, it is often because the kidney has become significantly enlarged in a newborn, toddler, or thin adult.

It is possible to sometimes feel a bloated bladder in the bottom area of the abdomen, right above the pubic bone.

Testing is essential to a doctor’s ability to make a diagnosis.

When a person exhibits symptoms suggesting an enlarged bladder, such as pelvic pressure or distention, the first diagnostic test often performed is bladder catheterization. This procedure involves inserting a hollow, soft tube through the urethra.

If the catheter removes a significant quantity of urine from the bladder, it indicates that the obstruction is located either in the bladder outlet or the urethra.

Before doing a bladder catheterization, many medical professionals may use ultrasonography to check if the bladder is already full with a significant volume of pee.

Imaging studies may be used to discover indications of obstruction, such as hydronephrosis or a site of the blockage when the existence or location of obstruction is uncertain.

Hydronephrosis is a condition in which fluid builds up in the kidneys.

For instance, ultrasonography is a test that is highly helpful in diagnosing most individuals (especially children and pregnant women) since it is quite accurate and does not subject the person being tested to any radiation.

On the other hand, the capacity of ultrasonography to precisely pinpoint the location of a blockage is not 100% reliable.

An option is something called computed tomography, or CT. The identification of stones, in particular, may be done quickly and with a high degree of precision using this method.

Conventional computed tomography (CT) requires patients to be exposed to substantial quantities of radiation. 

CT scans may now be acquired with much lower radiation exposure because of advancements in CT scanner technology and improved techniques for their use.

Especially for the detection of kidney stones, magnetic resonance imaging (MRI) is not as accurate as ultrasonography or CT.

However, MRI may be used if it is vital to avoid exposing the individual to radiation and if the location of the blockage cannot be observed using ultrasonography.

Examination of the urethra, prostate, and bladder may be performed by endoscopy using a specialized rigid or flexible endoscope called a cystoscope.

When trying to locate the source of an obstruction, a longer rigid or flexible endoscope, known as a ureteroscope, is inserted into the kidneys or ureters.

Objects that are causing obstruction can sometimes be removed with the help of a cystoscope, ureteroscope, or both of these instruments.

It is necessary to test both the blood and the urine. The findings of blood tests are often normal (especially if the blockage is partial or acute), but tests may indicate elevated levels of blood urea nitrogen (also frequently referred to as BUN), creatinine, or both.

If the obstruction has totally clogged both kidneys for more than a few hours. The findings of a urine study, also known as a urinalysis, are often normal.

However, white blood cells and red blood cells may be found if an obstruction is caused by a stone or a tumor, or if an infection worsens the blockage.

The goal of treatment is often to alleviate whatever is causing the blockage. For instance, whether the urethra is obstructed because of a benignly enlarged prostate or a malignant prostate, different treatment options would be considered.

 These options may include surgery, medicines (such as hormone therapy for prostate cancer), or dilators that widen the urethra.

It is possible that in order to remove stones that are blocking the flow of urine in the ureter or kidney, further procedures, such as lithotripsy or endoscopic surgery, will be required.

The urinary tract is drained if the reason for blockage cannot be quickly resolved, especially if there is an infection, acute renal failure, or significant discomfort. This is the case when the obstruction cannot be quickly repaired. 

Urine that has accumulated above an obstruction that cannot be easily relieved can be drained using a soft tube that is inserted through the back into the kidney (known as a nephrostomy tube) or by inserting a soft plastic tube that connects the bladder with the kidney. 

Both procedures are used when acute hydronephrosis is caused by an obstruction that cannot be easily relieved (ureteral stent). Nephrostomy tubes and ureteral stents may cause several complications, including infection, pain, and even displacement of the tube itself.

When an obstruction is suspected to be located in the urethra, medical professionals insert a catheter made of a flexible rubber into the bladder in order to drain urine from the body.

In children who have a blockage of the bladder or urethra, further imaging tests like voiding cystourethrography (VCUG) may be performed to determine the location of the obstruction.

This is the case the majority of the time. The imaging examination can determine whether or not such structures have any obstructions (for example, caused by birth defects).

It is also able to determine vesicoureteral reflux, which is when urine runs backwards from the bladder into the ureters.

This condition is responsible for urinary tract infections (UTIs) as well as blockage. X-rays are obtained as part of the VCUG procedure after a radiopaque substance (dye) has been injected into the bladder through a catheter. These X-rays are then taken.

In most cases, the obstruction can be removed, but if the removal process takes too long, the kidney may sustain lasting damage.

It is quite improbable that permanent kidney failure would occur until both kidneys have been blocked for some period of time, often at least a few weeks. This is due to the fact that one kidney that is properly functioning is sufficient to keep the person alive and well. 

The prognosis is also impacted by the underlying reason for the obstruction.

For instance, the likelihood of kidney damage being caused by a kidney stone is lower than the likelihood of kidney damage being caused by an untreated infection.

In most cases, persistent hydronephrosis caused by obstructions does not need immediate medical attention.

However, urinary tract infections and acute kidney failure are two potential complications of urinary tract obstruction that, if present, require prompt medical attention.