From the Guidelines
Urobilinogen in urine can have several benign causes that don't necessarily indicate disease, including dehydration, strenuous physical exercise, certain medications, consumption of foods with natural pigments, physiological variations, and pregnancy. When evaluating urobilinogen levels, it's essential to consider these benign causes, as they can lead to slight elevations without clinical significance. Normal urobilinogen levels in urine range from 0.1 to 1.0 Ehrlich units per deciliter, and mild elevations may occur due to various factors. Some key points to consider include:
- Dehydration, which concentrates urine components
- Strenuous physical exercise, which can temporarily alter liver metabolism
- Certain medications like sulfonamides and some antibiotics
- Consumption of foods with natural pigments like beets or blackberries that may affect urinary composition
- Physiological variations throughout the day, with higher levels typically appearing in afternoon urine samples due to normal diurnal variation in liver metabolism
- Pregnancy, which sometimes causes mild elevations due to hormonal changes affecting liver function It's crucial to note that urobilinogen is produced when bilirubin is metabolized by intestinal bacteria and partially reabsorbed into the bloodstream, so any factor that slightly increases this normal process without indicating pathology can cause benign elevations 1. If urobilinogen levels are only mildly elevated with no other concerning symptoms or abnormal test results, these benign causes should be considered before pursuing more extensive diagnostic workups.
From the Research
Benign Reasons for Urobilinogen in Urine
- Urobilinogen in urine can be caused by various factors, including benign effects of medications and foods 2
- A study published in 1991 developed a method for quantitating urobilinogen in feces, urine, bile, and serum, which can help in determining the cause of urobilinogen in urine 3
- Another study published in 1987 evaluated the accuracy of urine urobilinogen and bilirubin assays in predicting liver function test abnormalities, and found that urine urobilinogen has its greatest clinical utility as a screen when a normal/abnormal threshold of 2.0/4.0 mg/dL is used 4
- Certain medications, such as rifampicin, can cause hemolysis, which can lead to increased levels of urobilinogen in urine 5
- However, it is essential to note that urobilinogen in urine can also be a sign of an underlying pathological condition, and a thorough history and urinalysis are necessary to determine the cause 2
Related Factors
- Complete blood count (CBC) components, such as white blood cell count, neutrophil-to-lymphocyte ratio, and red cell distribution width, can be useful markers to predict cardiovascular and metabolic diseases, which may be related to urobilinogen in urine 6