Urinary incontinence: Pathology review


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Urinary incontinence: Pathology review

Renal system

Renal and ureteral disorders

Renal agenesis

Horseshoe kidney

Potter sequence











Renal tubular acidosis

Minimal change disease

Diabetic nephropathy

Focal segmental glomerulosclerosis (NORD)


Membranous nephropathy

Lupus nephritis

Membranoproliferative glomerulonephritis

Poststreptococcal glomerulonephritis

Goodpasture syndrome

Rapidly progressive glomerulonephritis

IgA nephropathy (NORD)

Lupus nephritis

Alport syndrome

Kidney stones


Acute pyelonephritis

Chronic pyelonephritis

Prerenal azotemia

Renal azotemia

Acute tubular necrosis

Postrenal azotemia

Renal papillary necrosis

Renal cortical necrosis

Chronic kidney disease

Polycystic kidney disease

Multicystic dysplastic kidney

Medullary cystic kidney disease

Medullary sponge kidney

Renal artery stenosis

Renal cell carcinoma


Nephroblastoma (Wilms tumor)

WAGR syndrome

Beckwith-Wiedemann syndrome

Bladder and urethral disorders

Posterior urethral valves

Hypospadias and epispadias

Vesicoureteral reflux

Bladder exstrophy

Urinary incontinence

Neurogenic bladder

Lower urinary tract infection

Transitional cell carcinoma

Non-urothelial bladder cancers

Renal system pathology review

Congenital renal disorders: Pathology review

Renal tubular defects: Pathology review

Renal tubular acidosis: Pathology review

Acid-base disturbances: Pathology review

Electrolyte disturbances: Pathology review

Renal failure: Pathology review

Nephrotic syndromes: Pathology review

Nephritic syndromes: Pathology review

Urinary incontinence: Pathology review

Urinary tract infections: Pathology review

Kidney stones: Pathology review

Renal and urinary tract masses: Pathology review


Urinary incontinence: Pathology review

USMLE® Step 1 questions

0 / 3 complete


USMLE® Step 1 style questions USMLE

of complete

A 75 year-old African-American male comes to the office because of continuous dribbling of urine which began one month ago. In addition, the patient endorses difficulty initiating and maintaining a urinary stream. Past medical records indicate that he has hypertension and type 2 diabetes mellitus. The patient has a 40-pack-year smoking history. His temperature is 37.0°C (98.6°F), blood pressure is 150/86 mmHg, pulse is 70/min, and respirations are 15/min. Cardiac, pulmonary, and abdominal examinations are non-contributory. Digital rectal exam reveals an enlarged, symmetrical, and smooth prostate. Laboratory study results are as follows:  
 Laboratory value  Result 
 Glucose  118 mg/dL 
 HbA1c  6.9% 
 Prostate-specific antigen (PSA)*  3.6 ng/ml 
*Normal PSA < 4.0 ng/ml

Which of the following is the most likely cause of the patient’s urinary symptoms?


Content Reviewers

Robyn Hughes, MScBMC

Yifan Xiao, MD


Anca-Elena Stefan, MD

Evan Debevec-McKenney

Marisa Pedron

Elizabeth Nixon-Shapiro, MSMI, CMI

In the Urology ward, two people are coming in. The first is Oleg, a 70 year old man who says that he frequently has to use the bathroom and also complains of a weak urinary stream. The second is Samantha, a 55 year old woman who says that she “pees” a little when she laughs. Samantha also has 2 children and both were born by vaginal delivery. Now, both these individuals seem to have urinary incontinence.

Urinary incontinence is a problem where the process of urination happens involuntarily, meaning that a person might urinate without intending to. This is particularly problematic because it affects a person’s personal hygiene as well as their social life in a way that can be very limiting.

Let’s talk about physiology real quick. Okay, so as urine flows from the kidneys into the bladder, the bladder starts to fill. Lining the bladder is a layer of transitional epithelium containing “umbrella cells”. These cells physically stretch out as the bladder fills, just like an umbrella opening up in slow-motion. This expansion is further aided by the relaxation of the muscular layer within the bladder’s walls, called the detrusor muscle. At some point, the bladder fills up with urine that will eventually exit the body through the urethra.

Now, the urethra is wrapped up in some muscles that can prevent urine from leaking out. The first one is the internal sphincter muscle, which is made of smooth muscle and is under involuntary control and typically opens up when the bladder is about half full. The second one is the external sphincter muscle, and it’s made of skeletal muscle and is under voluntary control. This is the reason that it’s possible to stop urine mid-stream by tightening up that muscle. Once urine has passed through the external sphincter muscle, it can no longer be stopped.


Urinary incontinence is a common condition that occurs when urine involuntarily leaks from the bladder, often through the internal and external sphincter muscles. There are several types of urinary incontinence, including urge incontinence, stress incontinence, and overflow incontinence.

Urge incontinence is typically caused by an overactive bladder, which can lead to sudden and strong urges to urinate that are difficult to control. Stress incontinence, on the other hand, is often due to increased pressure on the bladder, which can happen during physical activity, sneezing, or coughing. Overflow incontinence is caused by incomplete emptying of the bladder, leading to urine leakage due to bladder overfilling.

The treatment for urinary incontinence depends on the underlying cause and severity of the condition. Some common interventions include strengthening the external sphincter muscle by doing things like Kegel exercises, and catheterization or medications like alpha-blockers, which relax the smooth muscle to assist with urination.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "First Aid for the USMLE Step 1 2018, 28th Edition" McGraw-Hill Education / Medical (2017)
  4. "Effectiveness of preoperative pelvic floor muscle training for urinary incontinence after radical prostatectomy: a meta-analysis" BMC Urology (2014)
  5. "Prevalence of postpartum urinary incontinence: a systematic review" Acta Obstetricia et Gynecologica Scandinavica (2010)
  6. "Stress urinary incontinence in pregnant women: a review of prevalence, pathophysiology, and treatment" International Urogynecology Journal (2013)
  7. "Nonsurgical Management of Urinary Incontinence in Women: A Clinical Practice Guideline From the American College of Physicians" Annals of Internal Medicine (2014)
  8. "Benefits and Harms of Pharmacologic Treatment for Urinary Incontinence in Women" Annals of Internal Medicine (2012)

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