Urine: Physical and Chemical Properties

Urine is mostly water, which makes up around 95% of its volume. The remaining 5% consists of different solutes.

Urea, a byproduct of amino acid breakdown, is the second most abundant component of urine.

Other nitrogen-based wastes in urine include uric acid from nucleic acid breakdown and creatinine from the breakdown of creatine phosphate in skeletal muscles.

Small quantities of ions like sodium, potassium, calcium, magnesium, phosphate, sulfate, and bicarbonate are also present.

Healthy urine lacks blood, proteins, and white blood cells, and their presence may signal a pathological condition.

Freshly excreted urine is clear and varies in color from light to deep yellow. This color is due to urobilin, a pigment produced during the breakdown of hemoglobin.

It has a mild smell that can become ammonia-like as bacteria break down urea.

Certain foods, medications, and vitamin supplements can alter urine color. Further, cloudiness may suggest a urinary tract infection.