Urine Color
Urine Color in Urinalysis (UA)
Normally, urine color varies from light yellow to amber. This color is due to the presence of pigments called urochromes, which are formed during the breakdown of hemoglobin.
The intensity of the color depends on the concentration of dissolved organic and inorganic substances:
- With increased urine production (high fluid intake), the color becomes lighter and paler.
- With decreased diuresis (reduced urine volume), the color becomes more intense and darker.
Urine color can also change due to:
- Intake of certain medications such as riboflavin, aminophenazone, furazidin, metronidazole;
- Consumption of pigmented foods like beets, carrots, blueberries;
- Pathological conditions.
Pathological changes in urine color include:
- Hematuria — red color, often described as “meat slops,” indicates the presence of blood in urine.
- Leukocyturia, pyuria — milky-white color associated with pus presence.
- Bilirubinemia — dark brown or “beer” color appears with elevated bilirubin levels, for example, in jaundice.
- Hemo- or myoglobinuria — black or very dark urine color, seen in acute hemolytic anemia or muscle injury.
- Greenish-blue shades may occur with putrefactive processes in the gastrointestinal tract accompanied by pigment release.
Thus, urine color is an important diagnostic indicator reflecting both physiological factors (hydration, diet, medication intake) and the presence of various diseases of the urinary system and metabolism.