Urine and Urination
The kidneys produce urine by filtering several substances from the blood. These substances include excess water and waste products such as urea. Once formed, urine travels through the ureters to the bladder, where it is stored until the body is ready to expel it during urination. A healthy human bladder can comfortably accommodate approximately 450 milliliters of urine for a duration of two to five hours. It is worth noting that the bladder expands into a rounded shape when full and shrinks when empty.
Causes of Urine Color Change
A clear yellow urine is typically considered normal and indicates good health and hydration. However, various factors can lead to a change in urine color, which can be indicative of different health conditions. Below are some common urine colors and their meanings:
- Clear urine: This may indicate overhydration, a condition that is generally less dangerous compared to dehydration but can dilute essential salts in the body, leading to potential health issues.
- Dark yellow urine: This is usually normal but can suggest mild dehydration.
- Amber-colored urine: May indicate dehydration.
- Light orange urine: Might suggest dehydration or issues related to liver or bile ducts. It could also be a result of food dyes or excess vitamin B being excreted from the bloodstream.
- Orange urine: This color can be attributed to certain medications, notably Rifampin, Phenazopyridine, or Warfarin.
- Dark orange or brown urine: Could signal severe dehydration, jaundice, rhabdomyolysis, or Gilbert’s Syndrome.
- Pink urine: This might arise from the consumption of certain foods such as beets or blueberries, and in some cases, it may indicate serious health issues requiring immediate medical attention.
- Red urine: Known as hematuria, the presence of blood in the urine can be benign or may indicate kidney stones, infections, tumors in the urinary tract, prostate problems, lead or mercury poisoning, or porphyria, which encompasses rare genetic disorders. If red urine is present, a doctor should be consulted promptly.
- Green urine: This may result from eating asparagus, consuming food dyes, urinary tract infections, or certain medications such as Amitriptyline, Indomethacin, Cimetidine, or Promethazine. These medications can also cause blue urine.
- Blue urine: Often linked to food dyes, specific medications, or a genetic condition called familial hypercalcemia, which involves incomplete breakdown of tryptophan by the intestines.
- Dark brown or black urine: May result from various factors, including the consumption of large quantities of certain plants such as rhubarb or fava beans, specific medications like Chloroquine, Primaquine, Metronidazole, or Nitrofurantoin, or due to copper or phenol poisoning. The term melanuria is used to describe the presence of black urine in cases of melanoma.
- White or milky urine: This may indicate excessive protein intake, high levels of specific minerals like calcium or phosphate, or a urinary tract infection.
Characteristics of Urine
Urinalysis can be performed to assess the characteristics of an individual’s urine. Here are some key features of normal urine:
- Color: Normal urine ranges from pale yellow to amber, primarily due to the pigment urochrome.
- Transparency: A normal urine sample is initially clear but may become cloudy over time.
- pH Level: The pH of normal urine typically ranges between 4.8 and 7.5.
- Protein Content: Normally, large protein molecules are absent from urine. Their presence may suggest specific physical activities or certain health conditions.
- Glucose: Urine contains a small amount of glucose, typically between 0.01 to 0.03 grams per 100 ml.
- Specific Gravity: This measures urine concentration. A normal 24-hour urine sample has a specific gravity ranging from 1.002 to 1.030.
Video on Urinary Bacteria
Watch the video to learn more about urinary bacteria: