urinetests

Urine tests, or urinetests, are a group of laboratory analyses performed on urine samples to assess kidney function, detect diseases, monitor medical conditions, and screen for substances. They are commonly used in both clinical and research settings to provide information about the body's metabolic and excretory processes.

Specimens may be collected as random midstream, first-morning, clean-catch, or catheterized samples, depending on the test. Proper collection is important to minimize contamination and to ensure reliable results. Pretest factors such as recent fluid intake, exercise, and medications can also influence outcomes.

Common types include urinalysis (dipstick and microscopic), urine culture, urine protein-to-creatinine ratio, 24-hour urine collection, and pregnancy tests. Urinalysis combines chemical dipstick testing with microscopic examination to assess components such as glucose, protein, blood, ketones, pH, specific gravity, bilirubin, nitrites, and leukocytes, as well as cells and crystals seen under the microscope. Cultures identify bacterial growth and guide antibiotic selection. More specialized tests, like 24-hour urine collection, quantify certain substances over a day, and pregnancy tests detect human chorionic gonadotropin (hCG).

Interpreting results depends on clinical context. Values can be influenced by hydration status, recent meals or exercise, medications, and timing of collection. Contamination, assay limitations, and biological variability can cause false positives or negatives, so results are considered alongside symptoms and other tests.

Urine tests are used to evaluate urinary tract infections, kidney disease, diabetes management, pregnancy, dehydration, and metabolic or liver disorders. Urine drug testing is also employed in some employment, sports, clinical, and legal settings, subject to privacy protections and regulatory requirements.