Urine analysis is performed to examine urine composition and detect abnormalities. A 24-hour urine sample allows quantitative analysis of proteins, metabolites, and microorganisms. Urine is examined macroscopically for volume, color, odor, pH, and specific gravity. Chemical examination detects proteins, sugars, ketones, bilirubin, urobilinogen, and blood. Microscopic examination identifies crystals, casts, epithelial cells, and red and white blood cells. Urine dipsticks provide a convenient, rapid, qualitative analysis of various urine components.