 Hey everybody, Dr. O. This is where we're going to talk about the composition of urine. So why do we care so much about urine? Well, urine is filtered blood. So urine is a phenomenal way for us to learn about what's going on in our bloodstream. This is why your analysis, you might think we have so many more sophisticated techniques and technologies today for diagnosis, but a good old year analysis can still tell you a ton. I think they're actually underutilized. There are more sophisticated tests like urine organic acids profiles that can tell you about the buildup of metabolites in your blood as they spill over into your urine. We won't go through everything here, but I just want you to understand that you can learn a lot by looking at what's in urine. So here we see some urine. Let's go ahead and look at the normal urine characteristics. So first we have color. I can show you the, obviously the color of urine, I can show you the chart here in just a moment, but from pale yellow to deep amber, and there's obviously some variations that can occur there. But for a normal person, the color of urine and what the urine looks like and the volume of urine is going to depend on water intake, but also exercise. So how much are you sweating? How much are you losing water in other ways? Environmental temperature, so not just temperature, but humidity is a huge deal. Nutrient intake is going to play a role in the color of urine as well. There are lots of things, even some genetic conditions. So there are lots of things that can cause urine color to vary, but normal urine should be pale yellow to a deeper amber, but closer to pale yellow is better. But if you just took a multivitamin or vitamin C or riboflavin, these kind of things are going to have a big impact. Here we see just the hydration chart. For a normal healthy person, you want your urine to be that pale straw, pale yellow color. That means you're properly hydrated. If your urine is really dark, that's a sign that you're dehydrated. If someone has really clear urine and is producing a whole lot of it, though, that could mean that they're either over hydrated or they have conditions that lead to increased urine production, biggest one being diabetes malitis. So someone has diabetes, basically what's happening is as excess glucose spills into the urine, it's osmosis is water following solute. So this extra glucose is going to pull water with it. So a diabetic is not peeing a lot because they're thirsty. They're thirsty because they're peeing a lot. They have to produce excess urine to carry all that extra glucose out of their body, which means they're going to urinate more than they should. That's drawing water out through the kidneys, which has to be replaced by drinking it. So that's why a diabetic will be drinking more water or really thirsty all the time. And we can talk about the weight loss and everything else when we cover diabetes specifically. But there is also a condition that can be caused by a tumor in the hypothalamus called diabetes insipidus, which makes it so you don't have enough ADH, anti-diuretic hormone. And as you'll learn later, without anti-diuretic hormone, you could produce 27 liters of urine a day, which is clearly not compatible with life. So if you have a deficiency of anti-diuretic hormone, you could also have really, really clear urine, which wouldn't always be good. Food can certainly influence urine. They always talk about beets and blueberries and rhubarb being a good example. If your urine is pink or red, you need to be thinking blood, from a kidney stone or a tumor or something like that. If urine gets brown, they call it maybe a tea or a cola look to it. That can usually mean some sort of liver problems. These aren't everything. So that's going to be what urine should look like. Then we'll go back. We have some odor. So urine should be odorless. If you smell like an ammonia smell with urine, it's usually because it's been sitting around for a while. Because the ammonia in our body has turned into urea and then passed through in our urine. Your kidneys have about 21 grams of urea in it a day. Bacteria can metabolize that urea back to ammonia. So that ammonia smell is usually urine that's been around for a while. So if your bathroom smells like ammonia, it's probably not urine that's in the toilet. It's probably urine that's on the floor or something. Volume, we've already mentioned, that's going to be determined by hydration or some disease states. pH, pretty interesting. See a pretty wide range there. The normal pH of urine can be from 4 and 1 half to 8. That's going to be like a thousand-fold difference. So why do we see such huge changes in pH? It's to preserve your blood pH, basically. So the best example I can give you is when you exercise, your urine pH goes down. It might drop like two points. Your urine might drop from seven to five while you're exercising. That's because as you exercise, you're producing extra acids, carbonic acid, metabolic acids. Those acids are spilled over into your urine. You'd rather see a change of urine pH of two or three points from six to five or six to four or whatever, than see your blood pH drop. Because if your blood pH drops below 7.35, then you now have an acidosis condition. So this wild fluctuation in urine is really to preserve the pH in blood. So the gravity, it's always going to be above one. It's basically a measure of comparing any liquid to water. So pure water has a specific gravity of one. So the specific gravity is always going to be higher than one because there's always going to be solutes in it. You want this number to be close to one, though. The higher end of that, 1.032, that'd be someone that's dehydrated. There's a lot of solutes in their urine compared to the solvent water. We won't go through all these, but white blood cells, you shouldn't be seeing any leukocytes or white blood cells in your urine. If you do, that's evidence of a urinary tract infection. They're not excreted in the urine. They're going to be there fighting a UTI somewhere in your urinary tract. Protein, so there shouldn't be any protein, a really high protein meal can maybe cause some protein to be in your urine. But if you see protein in the urine, the biggest concern is that the glomerulus, the filter at the beginning of each nephron, is damaged in allowing proteins to leak through. Proteins are too large to, they shouldn't normally leak through. I don't know why, though, but I've also seen intense exercise can cause some leakage of protein into the urine. So there's a little bit of protein in the urine and someone's eating a high protein diet and they just got an exercising. I'm not as concerned about it, but protein in the urine should make you think some level of kidney damage. So ketones would be there if you're on a ketogenic diet. The reason the diabetics monitor ketone levels, though, is they want to make sure that they stay in ketosis or note ketones are produced. They don't want to reach a level where they could become or have diabetic ketoacidosis. Nitrites shouldn't be in the urine. Urine has what are called nitrates in it. So if you see nitrites, that means that there's bacteria, maybe like E. coli, that are in the area that are actually converting nitrates to nitrate. Of course, there shouldn't be blood in your urine. If there is, we've already mentioned think, stone, tumor, those kind of things. And then glucose. There should be no glucose in your blood, or sorry, there should be a lot of glucose in your blood. There should be no glucose in your urine unless you have so much glucose in your blood and so much glucose is being filtered into the kidneys that the kidneys can't reabsorb all of it, which would mean that by the time you see glucose in someone's blood, I would expect their blood sugar levels, blood glucose levels to be at least 185 milligrams per deciliter, because that's the point where you reach what's called this transport maximum or the saturation point where every transporter whose job it is is to reabsorb glucose is already as busy as it can be. So if you see glucose in the urine, you're definitely gonna wanna check the blood glucose levels. Okay, I think that's the basics of normal urine characteristics. I hope this helps. Have a wonderful day. Be blessed.