Urinens

Urinen, or urine, is a watery fluid produced by the kidneys as part of the body’s waste disposal system. It results from filtration of blood in the kidneys, followed by selective reabsorption and secretion along the nephron, and is excreted through the urinary tract.

In healthy individuals urine is primarily water, about 95%, with dissolved substances such as urea, creatinine, uric acid, and electrolytes including sodium, potassium, and chloride. Trace amounts of hormones, metabolites, pigments and other compounds contribute to its color and odor. The composition can vary with diet, hydration, and health status.

Normal urine volume depends on fluid intake and kidney function, typically around 1 to 2 liters per day. Physical characteristics vary with hydration: color ranges from pale yellow to amber; odor is normally mild. Chemical properties commonly include a pH near neutral (roughly 5.5 to 7.5) and a specific gravity around 1.005 to 1.030. Some substances may be present in small amounts, such as crystals or small amounts of mucus, without indicating disease.

Clinical use focuses on urinalysis, a routine diagnostic test. Dipstick analysis can detect pH, protein, glucose, ketones, bilirubin, blood, nitrites, and leukocyte esterase, while microscopic examination may reveal cells, crystals, casts, or bacteria. Abnormal findings can signal conditions such as diabetes mellitus (glucosuria, ketonuria), kidney disease (proteinuria, hematuria), urinary tract infection (nitrites, leukocytes, bacteria), dehydration (high specific gravity), or liver/biliary disease (bilirubin).

Collection and handling: urine samples are typically obtained by clean-catch midstream collection and must be stored properly if not analyzed immediately. Fresh collection and proper containers reduce contamination and improve test accuracy.