Flank pain

Jump to navigation Jump to search

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1],Associate Editor(s)-in-Chief: Jaspinder Kaur, MBBS[2]

Synonyms and Keywords:


Flank pain is a sensation of discomfort, distress, or agony in the part of the body below the rib and above the ilium, generally beginning posteriorly or in the midaxillary line and resulting from the stimulation of specialized nerve endings upon distention of the ureter or renal capsule. Similar pain is sometimes caused by extraurinary abnormalities.

Historical Perspective



Flank pain originating in the urinary system is caused by distention of the ureter or renal pelvis or distention of the renal capsule. The severity of the pain is directly related to the rapidity of the distention and not to the degree of distention. Therefore, a patient with acute distention of the ureter will have extremely severe pain. This patient usually has mild dilation of the ureter and no irreversible renal damage. However, a patient with a greatly dilated ureter and irreversible renal damage might have no pain or mild pain because the ureteral dilation has developed over a long period of time. Distention of the renal capsule causes a milder flank pain. This can be caused by aucte pyelonephritis, ureteral obstruction, or renal subcapsular hematoma. Kidney and ureteral pain is through visceral afferent fibers that accompany the sympathetic nerves of the lower thoracic and upper lumbar segments.

Flank pain due to ureteral obstruction: Flank pain that radiates to the ipsilateral testicle is usually caused by proximal ureteral or renal pelvic obstruction due to the common innervation of the testicle and the renal pelvis (T11–12). This pain usually originates in the posterior part of the flank and radiates to the testicle of the male or the labia of the female. The pain becomes lower and more anterior in the flank when the obstruction occurs in the middle third of the ureter. The pain is still lower, radiates to the scrotal skin (rather than the testicle), and is associated with voiding symptoms such as urinary frequency and urgency when the obstruction occurs at the level of the ureterovesical junction.

The degree of severity of the pain is directly related to the acuteness of the obstruction rather than the degree of obstruction. Therefore, a stone that passes into the ureter and suddenly becomes lodged in one position usually causes extremely severe pain. But flank pain can be very mild or absent in the presence of very severe but chronic obstruction. Mild and chronic flank pain associated with severe ureteral obstruction can produce irreversible renal damage. A stone passing through the ureter will often cause severe but intermittent pain. The intermittent pain is related to obstruction produced when the stone becomes lodged in the ureter. Therefore, each episode of pain is likely to be associated with a stone becoming lodged in a new and more distal position in the ureter. Flank pain is often associated with less specific symptoms including fever, nausea and vomiting, and tachycardia. Fever suggests infection proximal to the ureteral obstruction. Flank pain associated with fever requires a prompt diagnosis of ureteral obstruction and relief of the obstruction because infection proximal to the obstruction causes much more rapid renal damage than occurs with obstruction in the absence of infection. Also, the patient is susceptible to septicemia in the presence of infection proximal to a ureteral obstruction.

Gross or microscopic hematuria helps to confirm a urinary cause of the pain. Hematuria is occasionally absent with acute ureteral obstruction, however, and is often absent with chronic obstruction.

Congenital anomalies related flank pain Congenital anomalies such as ureteropelvic junction obstruction produce flank pain associated with a diuresis after oral intake of a large volume of fluid. Bilateral chronic ureteral obstruction or ureteral obstruction of a solitary kidney can be associated with symptoms of renal failure such as apathy, lethargy, anorexia, muscle twitching, headache, hypertension, and poor growth of a child. A dull or mild flank pain should make the clinician consider many possible causes including congenital ureteral obstruction, ureteral tumor or an extrinsic tumor compressing the ureter, acquired stricture of the ureter due to a previous operation or radiation therapy, retroperitoneal fibrosis, and a ureteral stone.

Extraurinary disorders related flank pain These diseases produce pain less characteristic of the typical "renal colic" seen with acute ureteral obstruction. Nevertheless, this vague, dull, mild flank pain is similar to the pain seen with chronic ureteral obstruction, making the differential diagnosis unclear. The correct diagnosis is made by thinking of all the diseases that have been discussed, considering the associated symptoms, physical examination, urinalysis, and performing carefully selected laboratory tests and radiographic studies.


Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Flank pain developed by WikiDoc.org

Common Causes

Flank pain developed by WikiDoc.org

Causes by Organ System

Cardiovascular Acute cortical necrosis, acute tubular necrosis, arteriovenous malformation, atheroemboli, fibromuscular dysplasia, hypertensive emergency, hypertensive urgency, ischemic colitis, renal artery aneurysm, renal artery dissection, renal infarction, renal vein thrombosis, ruptured abdominal aortic aneurysm, thromboemboli
Chemical/Poisoning No underlying causes
Dental No underlying causes
Dermatologic Herpes zoster
Drug Side Effect Acute papillary necrosis, crystal induced acute kidney injury, drug induced interstitial nephritis
Ear Nose Throat No underlying causes
Endocrine Adrenal hemorrhage, adrenocortical carcinoma
Environmental No underlying causes
Gastroenterologic Acute cholecystitis, appendicitis during pregnancy, ascending colon carcinoma, biliary colic, cholangitis, cholelithiasis, colitis, colon carcinoma, echinococcosis, gall stones, gallbladder empyema, hepatitis, hepatomegaly, inflammatory bowel disease, ischemic colitis, liver abscess
Genetic Xanthine oxydase deficiency
Hematologic Acute papillary necrosis, sickle cell disease, coagulopathy
Iatrogenic Infected penile prosthesis, nephrostomy, pelvic surgery
Infectious Disease Acute nephritis, acute pyelonephritis, adrenal hemorrhage, bilharziosis, candidemia, cholangitis, colitis, echinococcosis, emphysematous pyelitis, fungal bezoars, fungemia, fungus balls, herpes zoster, liver abscess, pelvic inflammatory disease, perinephric abscess, poststreptococcal glomerulonephritis, psoas abscess, renal abscess, renal mucormycosis, renal zygomycosis, urinary tract infection, urosepsis, urogenital tuberculosis
Musculoskeletal/Orthopedic Abdominal muscle spasm, abdominal muscle strain, abdominal muscle tear, disc disease, referred pain from back, spinal arthritis
Neurologic Neuralgia, neurogenic bladder
Nutritional/Metabolic Acute uric acid nephropathy, xanthine oxidase deficiency
Obstetric/Gynecologic Adnexitis, ectopic pregnancy, endometriosis, outwards pressure on the ribs from the growing uterus, ovarian cyst, ovarian torsion, ovarian tumor, pelvic inflammatory disease, pelvic surgery, polyembryoma, stretching of tissues around the uterus
Oncologic Adrenocortical carcinoma, angiomyolipoma, ascending colon carcinoma, bladder carcinoma, collecting duct carcinoma, colon carcinoma, oncocytoma, ovarian tumor, polyembryoma, renal cell carcinoma, transitional cell carcinoma, Wilms tumor
Ophthalmologic No underlying causes
Overdose/Toxicity No underlying causes
Psychiatric Somatoform disorder
Pulmonary No underlying causes
Renal/Electrolyte Acute cortical necrosis, acute kidney injury, acute nephritis, acute papillary necrosis, acute pyelonephritis, acute tubular necrosis, acute uric acid nephropathy, Alport's syndrome, angiomyolipoma, bladder carcinoma, calix diverticulum, collecting duct carcinoma, crystal induced acute kidney injury, drug induced interstitial nephritis, ectopic ureter, emphysematous pyelitis, fibromuscular dysplasia, glomerulonephritis, hydronephrosis, hypercalciuria, IgA nephropathy, Infected penile prosthesis, loin pain hematuria syndrome, malakoplakia, megaureter, nephrolithiasis, nephroptosis, nephrostomy, neurogenic bladder, obstructive uropathy, paroxysmal nocturnal haemoglobinuria, perinephric abscess, polycystic kidney disease, post renal transplantation, posterior urethral valves, poststreptococcal glomerulonephritis, reflux nephropathy, renal abscess, renal artery aneurysm, renal artery dissection, renal cell carcinoma, renal cyst, renal cyst infection, renal cyst rupture or hemorrhage, renal dystopia, renal infarction, Renal mucormycosis, renal papillary necrosis, renal trauma, renal vein thrombosis, renal zygmycosis, thin basement membrane nephropathy, transitional cell carcinoma, tubulointerstitial nephritis, ureteropelvic junction obstruction, urinary tract infection, urogenital tuberculosis, urolithiasis, urosepsis, Wilms' tumor
Rheumatology/Immunology/Allergy Acute nephritis, Alport's syndrome, Ormond's disease, paroxysmal nocturnal haemoglobinuria, post renal transplantation, poststreptococcal glomerulonephritis
Sexual No underlying causes
Trauma Abdominal muscle strain, abdominal muscle tear, perforation of a viscus, renal trauma
Urologic No underlying causes
Miscellaneous Exercise, lymphangioma, multifocal fibrosclerosis, retroperitoneal fibrosis, retroperitoneal hematoma, tuberous sclerosis

Flank pain developed by WikiDoc.org

Type Characteristics
Acute ureteral obstruction Stone, Blood clot, Papillary necrosis
Chronic ureteral obstruction Congenital anomaly, Tumor, Stricture of ureter, Previous surgery, Radiation therapy, Retroperitoneal fibrosis, Stone
Renal inflammation Acute pyelonephritis, Perinephric abscess
Renal tumor Renal cell carcinoma, Transitional cell carcinoma, Wilms" tumor
Trauma of kidney Calcium Oxalate Nephrolithiasis and Oxalate Nephropathy After Roux-en-Y Gastric Bypass, Nephrotoxic drug induced Nephropathy (Analgesics, NSAIDs)
Renal infarction Abdominal Aortic Aneurysm Repair
COngenital anomalies Vesicoureteral reflux, Solitary kidney, Ureteropelvic junction obstruction, Autosomal Dominant Polycystic Kidney Disease
Extraurinary Gallbladder disease, Appendicitis, Diverticulitis, Other gastrointestinal disease, Chest disease, Salpingitis

Causes in Alphabetical Order

Flank pain developed by WikiDoc.org

Differential Diagnosis

System Differential Diagnosis
Gastrointestinal Acute appendicitis, Diverticular disease, Bowel obstruction, Acute pancreatitis,
Gyanecological Ecotopic pregnancy, Ovarian cyst, Ovarian torsion
Musculoskeletal disorders Spinal arthritis, Muscle strain or tear

Epidemiology and Demographics

Risk Factors


Natural History, Complications, and Prognosis


Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings



Echocardiography or Ultrasound

CT scan


Other Imaging Findings

Other Diagnostic Studies


Medical Therapy


Primary Prevention

Secondary Prevention


  1. Wolffram, S.; Bisang, B.; Grenacher, B.; Scharrer, E. (1990). "Transport of tri- and dicarboxylic acids across the intestinal brush border membrane of calves". J Nutr. 120 (7): 767–74. PMID 2366111. Unknown parameter |month= ignored (help)
  2. Christodoulidou, M.; Thomas, M.; Sharma, SD. (2012). "Hydronephrosis and loin pain as a presentation of tubo-ovarian abscess developing after Mirena coil removal". BMJ Case Rep. 2012. doi:10.1136/bcr-03-2012-6108. PMID 22865801.
  3. Smith, HS.; Bajwa, ZH. (2012). "Loin pain hematuria syndrome-visceral or neuropathic pain syndrome?". Clin J Pain. 28 (7): 646–51. doi:10.1097/AJP.0b013e31823d47f3. PMID 22699133. Unknown parameter |month= ignored (help)

Template:WikiDoc Sources

Template:WikiDoc Sources