In patients with renal disorders, symptoms and signs may be nonspecific, absent until the disorder is severe, or both. Findings can be local (eg, reflecting kidney inflammation or mass), result from the systemic effects of kidney dysfunction, or affect urination (eg, changes in urine itself or in urine production). (See also Evaluation of the Urologic Patient.)
Dysuria is painful or uncomfortable urination, typically a sharp, burning sensation. Some disorders cause a painful ache over the bladder or perineum. Dysuria is an extremely common symptom in women, but it can occur in men and can occur at any age.
Acute kidney injury is a rapid decrease in renal function over days to weeks, causing an accumulation of nitrogenous products in the blood (azotemia) with or without reduction in amount of urine output. It often results from inadequate renal perfusion due to severe trauma, illness, or surgery but is sometimes caused by a rapidly progressive, intrinsic renal disease. Symptoms may include anorexia, nausea, and vomiting. Seizures and coma may occur if the condition is untreated. Fluid, electrolyte, and acid-base disorders develop quickly. Diagnosis is based on laboratory tests of renal function, including serum creatinine. Urinary indices, urinary sediment examination, and often imaging and other tests (including sometimes a kidney biopsy) are needed to determine the cause. Treatment is directed at the cause but also includes fluid and electrolyte management and sometimes dialysis.
Benign prostatic hyperplasia (BPH) is nonmalignant adenomatous overgrowth of the periurethral prostate gland. Symptoms are those of bladder outlet obstruction—weak stream, hesitancy, urinary frequency, urgency, nocturia, incomplete emptying, terminal dribbling, overflow or urge incontinence, and complete urinary retention. Diagnosis is based primarily on digital rectal examination and symptoms; cystoscopy, transrectal ultrasonography, urodynamics, or other imaging studies may also be needed. Treatment options include 5 alpha-reductase inhibitors, alpha-blockers, tadalafil, and surgery.
Chronic kidney disease (CKD) is long-standing, progressive deterioration of renal function. Symptoms develop slowly and in advanced stages include anorexia, nausea, vomiting, stomatitis, dysgeusia, nocturia, lassitude, fatigue, pruritus, decreased mental acuity, muscle twitches and cramps, water retention, undernutrition, peripheral neuropathies, and seizures. Diagnosis is based on laboratory testing of renal function, sometimes followed by renal biopsy. Treatment is primarily directed at the underlying condition but includes fluid and electrolyte management, blood pressure control, treatment of anemia, various types of dialysis, and kidney transplantation.
Cystic kidney disease may be congenital or acquired. Congenital disorders may be inherited as autosomal dominant disorders or autosomal recessive disorders or have other causes (eg, sporadic mutations, chromosomal abnormalities, teratogens). Some are part of a malformation syndrome (see table ).
Bladder cancer is usually transitional cell (urothelial) carcinoma. Patients usually present with hematuria (most commonly) or irritative voiding symptoms such as frequency and/or urgency; later, urinary obstruction can cause pain. Diagnosis is by cystoscopy and biopsy. Treatment is with fulguration, transurethral resection, intravesical instillations, radical surgery, chemotherapy, external beam radiation, or a combination.
Paraphimosis, entrapment of the foreskin in the retracted position, is a urologic emergency requiring reduction of the foreskin to its normal distal position enveloping the glans penis, in order to prevent necrosis of the glans.
Male sexual development and hormonal function depend on a complex feedback circuit involving the hypothalamus-pituitary-testes modulated by the central nervous system. Male sexual dysfunction can be secondary to hypogonadism, neurovascular or other disorders, or medication or recreational drug use.
Obstructive uropathy is structural or functional hindrance of normal urine flow, sometimes leading to renal dysfunction (obstructive nephropathy). Symptoms, less likely in chronic obstruction, may include pain radiating to the T11 to T12 dermatomes and abnormal voiding (eg, difficulty voiding, anuria, nocturia, and/or polyuria). Diagnosis is based on results of bladder catheterization, cystourethroscopy, and imaging (eg, ultrasonography, CT, pyelography), depending on the level of obstruction. Treatment, depending on cause, may require prompt drainage, instrumentation, surgery (eg, endoscopy, lithotripsy), hormonal therapy, or a combination of these modalities.
Renal replacement therapy (RRT) replaces nonendocrine kidney function in patients with renal failure and is occasionally used for some forms of poisoning. Techniques include continuous hemofiltration and hemodialysis, intermittent hemodialysis, and peritoneal dialysis. All modalities exchange solute and remove fluid from the blood, using dialysis and filtration across permeable membranes.
Many substances are secreted or reabsorbed in the renal tubule system, including electrolytes, protons, bicarbonate molecules, glucose, uric acid, amino acids, and free water. Dysfunction of these processes can result in clinical syndromes.
Hypertensive arteriolar nephrosclerosis is progressive renal impairment caused by chronic, poorly controlled hypertension. Symptoms and signs of chronic kidney disease may develop (eg, anorexia, nausea, vomiting, pruritus, somnolence or confusion), as may signs of end-organ damage secondary to hypertension. Diagnosis is primarily clinical, supported by ultrasonography and routine laboratory test findings. Treatment is strict blood pressure control and support of renal function.
Tubulointerstitial diseases are clinically heterogeneous disorders that share similar features of tubular and interstitial injury. In severe and prolonged cases, the entire kidney may become involved, with glomerular dysfunction and even renal failure. The primary categories of tubulointerstitial disease are
Urinary calculi are solid particles in the urinary system. They may cause pain, nausea, vomiting, hematuria, and, possibly, chills and fever due to secondary infection. Diagnosis is based on radiologic imaging, usually noncontrast helical CT. Treatment is with analgesics, antibiotics for infection, medical expulsive therapy, and, sometimes, minimally invasive surgical procedures (shock wave lithotripsy or endoscopic stone removal).
Urinary tract infections (UTIs) can be divided into upper tract infections, which involve the kidneys ( pyelonephritis), and lower tract infections, which involve the bladder ( cystitis), urethra ( urethritis), and prostate ( prostatitis). However, in practice, and particularly in children, differentiating between the sites may be difficult or impossible. Moreover, infection often spreads from one area to the other. Although urethritis and prostatitis are infections that involve the urinary tract, the term UTI usually refers to pyelonephritis and cystitis.