Urinalysis (U/A, aka Routine and Microscopy, R&M) is an array of tests performed on urine.
So urine glucose. That's your BSL's, right?
Not really, BSL's is sugar in blood. This is in urine. So urine glucose is from 4-6mmol/L. It's a little different from blood glucose, which varies a lot throughout the day, but is usually >4mmol/L even when not eating. When not eating, it should get higher than >8mmol/L, or that's starting to sound like diabetes. Usually, nearly ALL glucose is reabsorbed in the PCT of the kidney, but the capacity may be exceeded if BSL increases a lot, as it does in diabetes, the threshold being 40-45mmol/L.
Bilirubin in urine. That's bilirubinemia, right?
Again, not really. This is in urine, not blood. So the kidney can't touch unconjugated bilirubin, because it's not water soluble. However, with conjugated bilirubin, if the liver's function is impaired, or when drainage of bile is blocked, some conjugated bilirubin leaks out of the liver, and appears in the urine.
How does it differ from urobilinogen?
So this is where conjugated bilirubin is successfully excreted from the bile duct into the intestine, and converted by bacteria in the intestine into urobilinogen and stercobilinogen. Some of this is reabsorbed by the intestine into circulation, and filtered out by the kidneys. Urobilinogen is thus elevated in hemolytic and liver disease.
Ketones in urine. What makes it elevated?
They're products of metabolism of fatty acids, so they're made because fats are getting metabolized. This can happen because of starvation, malabsorption, inability to metabolize carbohydrates (as in diabetes), or losses from frequent vomiting.
Specific gravity, the weight of urine?
Sort of. We compare it with water, which is considered to be 1. It should normally be a little heavier than water. However, if it's heavy, it probably means there is dehydration, reducing the water content in comparison.
pH of urine. How does that work? Urine is acidic right? It sort of burns?
Neutral pH is 7, so yes, urine is sort of acidic, around 6.2. Acidic makes it more likely for uric acid stones to form, can be caused by diets high in protein. Urine can be basic, with diets high in fruit and veggies. Certain drugs can also make urine pH go both ways, depending on the drug.
Protein in urine. What does this mean?
So it usually means early kidney disease. Small proteins like albumin are let through by the glomerulus, and needs to be reabsorbed by the tubules.
Nitrites and leukocyte esterase in urine? Urine is usually sterile, right?
Nitrite indicates a specific cause of UTI's by Gram negative bacteria, that have enzymes that reduce nitrate present in urine, to nitrite, so it can mean E coli, Enterobacter, Klebsiella, Citrobacter, or Proteus. Leukocytes can sometimes be found in urine, due to vaginal contamination, but leukocyte esterase is found only in urinary infection.
It can also involve:
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