1. Kidney

Because of the liver, the right kidney is lower than the left. The lower pole of the right kidney may be palpable in thin patients, yet the left kidney is usually not palpable unless abnormally enlarged. To palpate the kidney, one hand is placed posteriorly over the costovertebral angle to push the kidney anteriorly, while the second hand is placed anteriorly under the costal margin. With inspiration, the kidney may be palpated between the two hands.

Auscultation of the upper abdominal quadrants in hypertensive patients may reveal a systolic bruit associated with renal artery stenosis or an arteriovenous malformation; however, aortic bruits or transmitted heart murmurs may give similar findings.

Patients with flank pain should be tested for hyperesthesia of the overlying skin by cotton swab or pin testing, as this may be secondary to nerve root irritation and radiculitis rather than being of renal origin. Musculoskeletal back pain is often provoked by positional changes and can be distinguished from renal colic due to ureteral obstruction by asking patients to bend to touch their toes, lean left and right, and twist their spine left and right.

2. Bladder

The normal adult bladder is not palpable unless filled with at least 150 mL of urine. Percussion is better than palpation in diagnosing the distended bladder. Dullness is appreciated over the full bladder and changes to tympany if the air-filled bowel is anterior to the bladder.

Bimanual examination under anesthesia may be helpful in the evaluation of patients with aggressive bladder neoplasms. In the male, the bladder is palpated between the abdominal wall and the rectum while in the female it is palpated between the abdominal wall and the vagina. A nonmobile or fixed bladder may not be resectable.

3. Penis

The foreskin must be retracted in the uncircumcised male to permit inspection of the urethral meatus and glans. The position of the urethral meatus and the presence of urethral discharge, inflammation, penile tumor, and skin lesions must be noted. In phimosis, the foreskin cannot be retracted over the glans. In paraphimosis, the foreskin has been left retracted behind the glans, resulting in painful engorgement and edema of the glans. If not attended to, this may result in glandular ischemia. Congenital anomalies of position of the urethral meatus are called hypospadias when the meatus is located on the ventral aspect of the penis, scrotum, or perineum and epispadias when it is located on the dorsal aspect of the penis. A thick yellow urethral discharge is seen in gonococcal urethritis, whereas a thin clear or white discharge is noted in nongonococcal urethritis. Palpation of the dorsal penile shaft for plaques of Peyronie disease and of the ventral surface for urethral tumors should be performed.

4. Scrotum and its Contents

The most common referral to the urologist concerning the scrotum is for evaluation of a mass. It is important to determine whether the lesion resides within the testicle or is related to the epididymis or cord structures. The testes are palpated between the fingertips of both hands. Normal testes measure 4.5 × 2.5 cm and are rubbery in consistency. The epididymis rests posterolateral to the testis and varies in its degree of testicular attachment. Masses arising from within the testes are usually malignant; those from the epididymis and spermatic cord structures are usually benign. Transillumination will frequently distinguish cystic (hydrocele or spermatocele) from solid lesions.

The history and physical examination can determine the diagnosis in the majority of cases. Tumors of the testis are usually painless, firm, solid lesions within the substance of the testis. These lesions often grow quickly and do not transilluminate.

Acute epididymitis is an acute infectious process and is associated with painful enlargement of the epididymis. Fever and irritative voiding symptoms are common. In advanced states, the infection can spread to the testis, making the distinction between the epididymis and the testicle difficult on physical examination. The entire scrotal contents may be painful on palpation, yet relief may be offered to the supine patient by elevation of the scrotum above the pubic symphysis (Prehn sign).

A hydrocele is a collection of fluid between the two layers of the tunica vaginalis. The diagnosis is readily made by transillumination. Hydroceles are typically benign but may be reactive or secondary to another etiology, such as an epididymoorchitis, torsion of appendix testis, or rarely due to a testicular neoplasm. Thus, evaluation with a scrotal ultrasound is often necessary.

A varicocele is engorgement of the internal spermatic veins above the testis. Varicoceles occur more commonly on the left side than the right due to the venous drainage patterns of the spermatic veins. Varicoceles should diminish in size or disappear with the patient in the supine position. The sudden onset of a right varicocele should raise the question of a retroperitoneal malignancy resulting in obstruction of the right spermatic vein.

Torsion of the testis typically occurs in the 10- to 20-year age group and presents with acute onset of pain and swelling within the testis, along with nausea. Examination reveals a painful testis that may reside higher within the scrotum in relation to the other testis. The acute onset, lack of voiding symptoms, and the different age distribution may help distinguish it from epididymitis.

Torsion of the appendices of the testis or epididymis may be indistinguishable from torsion of the testis and affects a similar age group as torsion of the testis. On occasion a small palpable lump on the superior pole of the testis or epididymis is discernible that may appear blue when the skin is pulled tautly over it ("blue dot sign").

5. Rectal Examination in the Male

External inspection for anal pathology (fissures, warts, carcinoma, hemorrhoids) should be performed first. Upon insertion of the finger, anal tone can be estimated and a bulbocavernosus reflex can be elicited. As the anal and urinary sphincter derive from a common innervation, clues to neurogenic disorders may be obtained. The entire prostate is then examined and palpated, with attention being directed toward size and consistency. The normal prostate is approximately 4 × 4 cm and weighs 25 g. Normal consistency is similar to the contracted thenar eminence with the thumb opposed to the little finger. Rubbery enlargement of the prostate is noted in benign prostatic hyperplasia. Firm nodules are concerning for prostate carcinoma. Induration may be perceived with carcinoma but also with chronic inflammation. The remainder of the rectum is then examined to exclude primary rectal disease.

6. Pelvic Examination in the Female

Examination of the introitus should include inspection for atrophic changes, ulcers, discharge, and warts. Prolapse of the bladder (cystocele), rectum (rectocele), or vaginal vault (enterocele) may be apparent on gross inspection or speculum examination. The urethral meatus can be inspected for caruncles (more commonly seen in postmenopausal patients as a reddened area at the inferior margin of the meatus) and palpated for tumors or diverticula. Bimanual examination of the bladder, uterus, and adnexa should be performed with two fingers in the vagina and one hand on the abdomen, and attention is directed toward abnormal masses.

1. pH

There is no role for dipstick urinalysis screening for urinary tract disorders in asymptomatic adults except for pregnant women. Urinary pH (range 5.0-8.0) may be helpful in the diagnosis and treatment of some urologic conditions. Alkaline urine in a patient with a urinary tract infection suggests the presence of a urea-splitting organism, most commonly Proteus mirabilis, but also some strains of Klebsiella, Pseudomonas, Providencia, and Staphylococcus. Failure to acidify the urine below a pH of 5.5 despite a metabolic acidosis suggests a distal renal tubular acidosis.

2. Protein

Dipsticks using bromophenol blue can detect protein in concentrations exceeding 10 mg/dL. But it measures albumin and is not sensitive for the light chain of immunoglobulins (Bence Jones proteins). False-positive results are seen in urine containing numerous leukocytes or epithelial cells.

3. Urobilinogen and Bilirubin

Urobilinogen is formed from the catabolism of conjugated bilirubin in the gut by bacteria, and the majority is cleared by the liver. Normally, only 1-4 mg of urobilinogen is excreted in the urine per day. Hemolytic processes or hepatocellular disease can lead to increased urinary levels, while complete biliary obstruction or broad-spectrum antibiotics that alter the gut bacterial flora may result in absent urinary urobilinogen. Normally no bilirubin is detected by urinary dipstick, since only concentrations greater than 0.4 mg/dL are detectable. Conditions manifesting elevated conjugated bilirubin in the serum will result in higher urinary levels. Ascorbic acid may cause false-negative results, while phenazopyridine may cause false-positive results.

4. Glucose and Ketones

Only small amounts of glucose are normally excreted in the urine, and these levels are below the sensitivity of the dipstick. Any positive finding requires evaluation for diabetes. The test is specific for glucose and does not cross-react with any other sugars. Ascorbic acid or elevated ketones may result in false-negative results.

Ketones are not normally found in the urine, but fasting, post-exercise states, and pregnancy may result in elevated urinary ketones. The urine of patients with diabetes mellitus often contains elevated urinary ketone levels prior to an elevation in serum levels. False-positive results occur with dehydration or in the presence of levodopa metabolites, mesna (sodium mercaptoethanesulfonate), and other sulfhydryl-containing compounds.

5. Nitrites

Normally, the urine does not contain nitrites. Many gram-negative bacteria can reduce nitrate to nitrite, thus an indicator of bacteriuria. However, the low sensitivity of the test requires clarification. Adequate numbers of bacteria must be present (10⁵ organisms/mL), nitrates must be available in the urine, and the bacteria must be in contact with the urine for a sufficient time (usually 4 hours). Therefore, the first morning voided sample is preferable. False-negative results may be due to non-nitrate-reducing organisms, frequent urination, dilute or acidic urine (pH < 6.0), and the presence of urobilinogen. False-positive results are usually secondary to contaminated specimens, so that bacteria are indeed present in the sample yet not present in the urinary tract.

6. Leukocyte Esterase

Leukocyte esterase is an enzyme produced by white cells. The dipstick detects leukocytes in the urine, which is thus suggestive but not diagnostic for bacteria. False-positive tests result from specimen contamination. False-negative tests result from high specific gravity, glycosuria, the presence of urobilinogen, and medications, including rifampin, phenazopyridine, and ascorbic acid.

7. Blood

The urinary dipstick for blood measures intact erythrocytes, free hemoglobin, and myoglobin. False-positive results in women may occur as a result of contamination at collection with menstrual blood. Concentrated urine may also cause a false-positive result, as patients normally excrete 1000 erythrocytes per milliliter of urine. Vigorous exercise and vitamins or foods associated with high oxidant levels may also give a false-positive result. High ascorbic acid levels may give a false-negative result.

1. Leukocytes

The presence of more than five leukocytes per high-power field is considered significant pyuria. Leukocytes in the urine are indicative of injury to the urinary tract, which may or may not be due to infection. Other causes of pyuria include stones, strictures, neoplasm, genitourinary tuberculosis, glomerulonephropathy, or interstitial cystitis. Leukocyte counts will vary by the state of hydration, method of collection, and degree of injury to the urinary tract.

2. Erythrocytes

The presence of more than two erythrocytes per high-power field on a single occasion with an adequate collection is considered significant and warrants further investigation. (See Evaluation of Hematuria, below.) The appearance of the red cells may provide a clue to their origin within the urinary tract. Dysmorphic (irregularly shaped) cells have an uneven distribution of hemoglobin and cytoplasm, and usually indicate glomerular disease. Red cells that are round, with evenly distributed hemoglobin, suggest disease along the epithelial lining of the urinary tract. All patients with hematuria (even those taking antiplatelet agents and anticoagulants) require further diagnostic workup; morphology, though of interest, is not of sufficient accuracy to allow firm diagnostic conclusions.

3. Epithelial Cells

The presence of squamous epithelial cells in the urinary sediment is indicative of contamination and thus requires a repeat collection either through clean catch or sterile catheterization. Transitional epithelial cells are occasionally noted in normal urinary sediment, but if present in large numbers or clumps they cause concern about possible neoplasm. Urine cytology is not routinely recommended.

4. Bacteria and Yeasts

The identification of organisms in an uncontaminated specimen implies infection, which must be confirmed by culture. The presence of several organisms per high-power field usually correlates with a culture count of greater than or equal to 10⁵ organisms per milliliter. Gram staining may further aid in characterizing the organism. Candida albicans is the most common yeast seen in the urine, and characteristic budding and clumps are typically observed. For yeast, colony count per milliliter does not necessarily correlate with the severity of infection.

5. Casts

Casts are formed in the distal tubules and collecting ducts as a result of Tamm-Horsfall mucoprotein precipitation (the most common excreted protein in urine). They congregate near the edges of the coverslip and are detected best in a fresh specimen viewed under low power. If the urine is devoid of cells, hyaline casts are formed. Casts with entrapped red cells are indicative of glomerulonephritis or vasculitis. Leukocyte casts are suggestive of pyelonephritis. Epithelial casts in small numbers are normal, but in large numbers they suggest intrinsic kidney disease. Granular casts result from degeneration of other cellular casts and also suggest intrinsic kidney disease.

6. Crystals

Uric acid, oxalate, and cystine crystals are more often precipitated in acid urine, while phosphate crystals are more commonly seen in alkaline urine. The presence of uric acid, phosphate, and oxalate crystals can occur in patients with a history of kidney stones but can also occur in the absence of stones as a nonspecific finding in association with dehydration and concentrated urine. Cystine crystals, with a characteristic hexagonal benzene ring shape, are seen only in patients with cystinuria and are thus pathologic.