Most children with vesicoureteral reflux are asymptomatic. Vesicoureteral reflux may be diagnosed as a result of further evaluation of dilation of the kidney or ureters draining urine from the kidney while in utero as well as when a sibling has VUR (though routine testing in either circumstance is controversial). Reflux also increases risk of acute bladder and kidney infections, so testing for reflux may be performed after a child has one or more infections.

In infants, the signs and symptoms of a urinary tract infection may include only fever and lethargy, with poor appetite and sometimes foul-smelling urine, while older children typically present with discomfort or pain with urination and frequent urination.

Vesicoureteral reflux (VUR), also known as vesicoureteric reflux, is a condition in which urine flows retrograde, or backward, from the bladder into the ureters/kidneys. Urine normally travels in one direction (forward, or anterograde) from the kidneys to the bladder via the ureters, with a 1-way valve at the vesicoureteral (ureteral-bladder) junction preventing backflow. The valve is formed by oblique tunneling of the distal ureter through the wall of the bladder, creating a short length of ureter (1–2 cm) that can be compressed as the bladder fills. Reflux occurs if the ureter enters the bladder without sufficient tunneling, i.e., too "end-on".

The signs and symptoms of hydronephrosis depend upon whether the obstruction is acute or chronic, partial or complete, unilateral or bilateral. Hydronephrosis that occurs acutely with sudden onset (as caused by a kidney stone) can cause intense pain in the flank area (between the hips and ribs). Historically, this type of pain has been described as "Dietl's crisis". Conversely, hydronephrosis that develops gradually will generally cause either attacks of a dull discomfort or no pain. Nausea and vomiting may also occur. An obstruction that occurs at the urethra or bladder outlet can cause pain and pressure resulting from distension of the bladder. Blocking the flow of urine will commonly result in urinary tract infections which can lead to the development of additional stones, fever, and blood or pus in the urine. If complete obstruction occurs, kidney failure may follow.

Blood tests may show impaired kidney function (elevated urea or creatinine) or electrolyte imbalances such as hyponatremia or hyperchloremic metabolic acidosis. Urinalysis may indicate an elevated pH due to the secondary destruction of nephrons within the affected kidney. Physical examination may detect a palpable abdominal or flank mass caused by the enlarged kidney.

Prenatally diagnosed hydronephrosis (fluid-filled kidneys) suggest post-natal follow-up examination.

The strongest neo-natal presentation is urinary tract infection. A hydronephrotic kidney may present as a palpable abdominal mass in the newborn, and may suggest an ectopic ureter or ureterocele.

In older children, ureteral duplication may present as:

- Urinary tract infection - most commonly due to vesicoureteral reflux (flow of urine from the bladder into the ureter, rather than vice versa).

- Urinary incontinence in females occurs in cases of ectopic ureter entering the vagina, urethra or vestibule.

The symptoms of reflux nephropathy are comparable to nephrotic syndrome and infection of the urinary tract, though some individuals may not exhibit any evidence (symptom) of reflux nephropathy.

The underlying calyces lose their normal concave shape and show clubbing.

Urologic disease can involve congenital or acquired dysfunction of the urinary system.

Kidney diseases are normally investigated and treated by nephrologists, while the specialty of urology deals with problems in the other organs. Gynecologists may deal with problems of incontinence in women.

Diseases of other bodily systems also have a direct effect on urogenital function. For instance, it has been shown that protein released by the kidneys in diabetes mellitus sensitises the kidney to the damaging effects of hypertension.

Diabetes also can have a direct effect on urination due to peripheral neuropathies which occur in some individuals with poorly controlled diabetics.

Hydronephrosis—literally "water inside the kidney"—refers to distension and dilation of the renal pelvis and calyces, usually caused by urinary retention due to obstruction of the free flow of urine from the kidney. Untreated, it leads to progressive atrophy of the kidney. One or both kidneys may be affected. In cases of hydroureteronephrosis, there is distention of both the ureter and the renal pelvis and calices.

Duplicated ureter or Duplex Collecting System is a congenital condition in which the ureteric bud, the embryological origin of the ureter, splits (or arises twice), resulting in two ureters draining a single kidney. It is the most common renal abnormality, occurring in approximately 1% of the population. The additional ureter may result in a ureterocele, or an ectopic ureter.

Neoplasm should be considered in any patient presenting with NLD obstruction.In patients with an atypical presentation, including younger age and male gender, further workup is appropriate. Bloody punctal discharge or lacrimal sac distension above the medial canthal tendon is also highly suggestive of neoplasm.

Granulomatous disease, including sarcoidosis, granulomatosis with polyangiitis, and midline granuloma, may also lead to NLD obstruction.

It is thought to be congenital or the consequence of vesicoureteral reflux.

Posterior urethral valve (PUV) disorder is an obstructive developmental anomaly in the urethra and genitourinary system of male newborns. A posterior urethral valve is an obstructing membrane in the posterior male urethra as a result of abnormal "in utero" development. It is the most common cause of bladder outlet obstruction in male newborns. The disorder varies in degree, with mild cases presenting late due to milder symptoms. More severe cases can have renal and respiratory failure from lung underdevelopment as result of low amniotic fluid volumes, requiring intensive care and close monitoring. It occurs in about one in 8000 babies.

The classic manifestation of bladder exstrophy presents with:

- A defect in the abdominal wall occupied by both the exstrophied bladder as well as a portion of the urethra

- A flattened puborectal sling

- Separation of the pubic symphysis

- Shortening of a pubic rami

- External rotation of the pelvis.

Females frequently have a displaced and narrowed vaginal orifice, a clitoris, and divergent labia.

Renal failure is defined by functional impairment of the kidney. Renal failure can be acute or chronic, and can be further broken down into categories of pre-renal, intrinsic renal and post-renal.

Pre-renal failure refers to impairment of supply of blood to the functional nephrons including renal artery stenosis. Intrinsic renal diseases are the classic diseases of the kidney including drug toxicity and nephritis. Post-renal failure is outlet obstruction after the kidney, such as a kidney stone or prostatic bladder outlet obstruction.

Renal failure may require medication, dietary and lifestyle modification and dialysis.

Primary renal cell carcinomas as well as metastatic cancers can affect the kidney.

Infants with the disorder exhibit an inverted smile; they appear to be crying when they are actually smiling, in conjunction with uropathy. They also may be affected by hydronephrosis. Symptoms of this disease can start at very young ages. Many people with this syndrome will die in their teens to early 20s because of the renal failure (uropathy) if not diagnosed and treated. Children with the syndrome have abnormal facial development that cause an inverted smile, nerve connections are however normal. When attempting to smile, the child will appear to cry. Urinary problems arise as a result of a neurogenic bladder. Most patients older than the age of toilet training, present with enuresis, urinary-tract infection, hydronephrosis, and a spectrum of radiological abnormalities typical of obstructive or neurogenic bladders. Radiological abnormalities include things such as: trabeculated bladder, vesicoureteral reflex, external sphincter spasm, pyelonephritis, hyperreflexic bladder, noninhibited detrusor contraction, etc.. Urinary abnormalities might result in renal deterioration and failure. This can be prevented by taking proper measures to restore normal micturition and by taking antibiotics to prevent infections. In some cases, the affected patients become hypertensive and progress to end-stage renal disease, while others become uremic. Additionally, most patients suffer from constipation.

Early detection of this syndrome is possible through the peculiar faces that children present.

Ask-Upmark kidneys are a cause of secondary hypertension that can be curable.

Horseshoe kidney, also known as "ren arcuatus" (in Latin), renal fusion or super kidney, is a congenital disorder affecting about 1 in 600 people, more common in men.

In this disorder, the patient's kidneys fuse together to form a horseshoe-shape during development in the womb. The fused part is the isthmus of the horseshoe kidney.

Fusion abnormalities of the kidney can be categorized into two groups: horseshoe kidney and crossed fused ectopia. The 'horseshoe kidney' is the most common renal fusion anomaly.

When a diagnosis of multicystic kidney is made in utero by ultrasound, the disease is found to be bilateral in many cases. Those with bilateral disease often have other severe deformities or polysystemic malformation syndromes. In bilateral cases, the newborn has the classic characteristic of Potter's syndrome.

The bilateral condition is incompatible with survival, as the contralateral system frequently is abnormal as well. Contralateral ureteropelvic junction obstruction is found in 3% to 12% of infants with multicystic kidney and contralateral vesicoureteral reflux is seen even more often, in 18% to 43% of infants. Because the high incidence of reflux, voiding cystourethrography usually has been considered advisable in all newborns with a multicystic kidney.

Prune-belly triad consists of: Cryptorchidism, abdominal wall defects and genitourinary defects:

- A partial or complete lack of abdominal wall muscles. There may be wrinkly folds of skin covering the abdomen.

- Cryptorchidism (undescended testicles) in males

- Urinary tract abnormality such as unusually large ureters, distended bladder, accumulation and backflow of urine from the bladder to the ureters and the kidneys (vesicoureteral reflux)

Other Symptoms include:

- Frequent urinary tract infections due to the inability to properly expel urine.

- Ventricular septal defect

- Malrotation of the gut

- Club foot

- Later in life, a common symptom is post-ejaculatory discomfort. Most likely a bladder spasm, it lasts about two hours.

- Musculoskeletal abnormalities include pectus excavatum, scoliosis, and congenital joint dislocations including the hip. Diagnosis of prune belly syndrome necessitates a thorough orthopaedic evaluation because of the high prevalence of associated musculoskeletal abnormalities.

Underactive Bladder Syndrome (UAB) describes symptoms of difficulty with bladder emptying, such as hesitancy to start the stream, a poor or intermittent stream, or sensations of incomplete bladder emptying. The physical finding of detrusor pressurization of insufficient strength or duration to ensure timely and efficient bladder emptying is properly termed "detrusor underactivity" (DU) (Abrams et al., 2002). Historically, UAB and DU (as well as others such as 'bladder underactivity') have been often used interchangeably (Rigby D, 2005), leading to both terminologic and pathophysiologic confusion.

Patients with UAB have a diminished sense of bladder filling and consequently are often found to have DU as an underlying finding, however bladder outlet obstruction and less frequently volume hypersensitivity ("OAB") can be associated with UAB symptoms (Chapple et al., 2015).

In patients with this condition, the central portion of the kidney may be found just inferior to the inferior mesenteric artery because the normal embryologic ascent of the kidneys is arrested by its presence in people with central fusion of the kidneys. Horseshoe kidney is often asymptomatic, though persons affected by this condition may experience nausea, abdominal discomfort, kidney stones and urinary tract infections at greater frequency than those without renal fusion. There is currently no treatment for renal fusion other than symptomatic treatment.

Imaging Findings -

The 2 kidneys on opposite sides of the body with the lower poles fused in midline. Midline or symmetrical fusion (90% of cases).

May be missed on US, therefore pay careful attention to identification of lower poles of kidneys.

Renal long axis medially orientated,

Lower poles with curved configuration, elongation and poorly defined

Isthmus crosses midline anterior to spine and great vessels.

US for diagnosis in utero

IVP followed by CT or scintigraphy for pre-operative assessment

Variant arterial supply -

Bilateral renal arteries,

Inferior mesenteric Artery,

Arteries arising from aorta or common iliac, internal iliac, external iliac or inferior mesenteric arteries.

The lower poles of these kidneys fuse in the midline anterior to the aorta and spine. The isthmus is usually located at L4/5 level between the aorta and IMA.

Nuclear medicine (DMSA) scan confirms horseshoe kidney with fusion of both renal lower poles.

Posterior urethral obstruction was first classified by H. H. Young in 1919. The "verumontanum", or mountain ridge, is a distinctive landmark in the prostatic urethra, important in the systemic division of posterior valve disorders:

- Type I - Most common type; due to anterior fusing of the "plicae colliculi", mucosal fins extending from the bottom of the verumontanum distally along the prostatic and membranous urethra

- Type II - Least common variant; vertical or longitudinal folds between the verumontanum and proximal prostatic urethra and bladder neck

- Type III - Less common variant; a disc of tissue distal to verumontanum, also theorized to be a developmental anomaly of congenital urogenital remnants in the bulbar urethra

Dewan has suggested that obstruction in the posterior urethra is more appropriately termed congenital obstructions of the posterior urethral membrane (COPUMs), a concept that has come from an in-depth analysis of the historical papers, and evaluation of patients with a prenatal diagnosis that has facilitated video recording of the uninstrumented obstructed urethra. The congenital obstructive lesions in the bulbar urethra, named Type III Valves by Young in 1919, have been eponymously referred to as Cobb's collar or Moorman's ring. For each of the COPUM (Posterior Urethra) and Cobb's (Bulbar Urethra) lesions, the degree of obstruction can be variable, consistent with a variable expression of the embryopathy. The now nearly one hundred year old nomenclature of posterior urethral valves was based on limited radiology and primitive endoscopy, thus a change COPUM or Cobb's has been appropriate.

Bladder exstrophy (also known as ectopia vesicae) is a congenital anomaly that exists along the spectrum of the exstrophy-epispadias complex and most notably involves protrusion of the urinary bladder through a defect in the abdominal wall. Its presentation is variable, often including abnormalities of the bony pelvis, pelvic floor, and genitalia. The underlying embryologic mechanism leading to bladder exstrophy is unknown, though it is thought to be in part due to failed reinforcement of the cloacal membrane by underlying mesoderm.

Urofacial syndrome ( or hydronephrosis with peculiar facial expression), is an autosomal recessive congenital disorder characterized by inverted facial expressions in association with obstructive disease of the urinary tract. The inverted facial expression presented by children with this syndrome allows for early detection of the syndrome, this inverted smile is easy to see when the child is smiling and laughing. Early detection is vital for establishing a better prognosis as urinary related problems associated with this disease can cause harm if left untreated. Incontinence is another easily detectable symptom of the syndrome that is due to detrusor-sphincter discoordination, although it can easily be mistaken for pyelonephritis.

It may be associated with "HPSE2".