Caitlin Whyte (Host): This is Flourish. I'm Caitlin Whyte. Today, Dr. Carlos Zayas is joining us; a distinguished Nephrologist and the Medical Director of the Renal and Pancreas Transplant Program. We're going to explore the real impact of dehydration, uncovering its often overlooked effects on your mind and body. Doctor, what are some surprising signs of dehydration that people might not recognize?

Carlos Zayas, MD: To feel like you're starting to get dehydrated is when your mouth gets dry. Now, there are medications that can make you feel that way, but granted that you're not taking any medications that will affect the production of saliva, dry mouth is another example of early signs of dehydration. When some someone comes to you and said, I'm feeling weak, weakness is another early sign of dehydration.

People don't realize that when the fluid volume in their bodies is low, they might feel just simply weak. And that's one of the early signs along with tiredness. And if it's more severe, palpitations. Now, when the dehydration becomes more severe, especially with people who had other medical conditions, especially elderly patients, and they might develop confusion and at times irritability.

So they get, they get angry or they get frustrated or confused, not knowing why. And it could be just simply as the fluid status is low, they're dehydrated.

Host: And how does dehydration affect how we think, feel, and function day to day?  

Carlos Zayas, MD: Well, dehydration can affect your day-to-day activities in many ways. First off, if you're dehydrated, your blood pressure drop so you feel tired, you're less likely to be active. You're less active, less willing to move around, to walk, go upstairs, or even do your day to day activities of work. They can also make you feel anxious, because you might develop tachycardia, right?

So your heart rate goes up and you feel your heart like fluttering or having this palpitations that can make you feel weird, right? Dehydration can also affect your joints. It might affect the way you feel your joints when you walk, when you go up the stairs, when you're trying to work out. You may have more joint pain, more,discomfort when you're doing physical activity. And, obviously if you're tired and associated with dehydration, you might get sleepy easily and you might be less productive at work and, more irritable, right? So you might be more likely to react to, something that otherwise would not make you angry or upset.

Host: Can dehydration impact digestion, skin and joint health as well?

Carlos Zayas, MD: Yeah, so, the amount of body fluid that we have, will affect the way many organs and systems perform their functions. For instance, digestion in particular is very important. If, if you think about digestion of food requires the production of gastric secretions to produce acid, which helps digest proteins and fat in the stomach, and the movement of food through the intestine and the absorption of nutrients and vitamins, proteins, fat and carbohydrates is affected by the excess or the limited amount of fluid. For instance, if you are dehydrated, you get constipated. If you get constipated, you have abdominal pain. If you have then diarrhea, you can get dehydrated from too much loss of fluid through the gastrointestinal system.

So, by all means, fluid intake, dehydration, lack of fluid will affect digestion in all aspects. That's one part. In terms of the skin, if you think about we humans, our body is 70% water. So the integrity of, of your skin, what we call the skin turgor the, the strength of the skin is affected by the water composition, how much you have.

So you're more likely to get very dry skin, scaly skin, more likely to have bruises and injury to your skin when the skin is dry versus when the skin is at a normal state or turgor. And then we mentioned these joints, right? In order to allow the movement of two bones, the joint basically allowed two pieces of bone to coordinated movement, right?

There's a, like a cushion, like a shook absorber between the bones, and there's a, this sac that we call it synovial sac, which contains synovial fluid. Synovial fluid is a very thick material that is mostly water. And so when you're dehydrated that sac is, moreflexible. It is smaller, slimmer and it, it will not allow the, the normal joint, the movement of the joint affecting the way you perform.

So, all those organ systems and tissues would be affected by dehydration, as I mentioned in various ways. So the human body cannot function properly, without the necessary amount of body fluid.

Host: So what are some effective ways to stay hydrated beyond just drinking water?

Carlos Zayas, MD: Beyond drinking water, there are other ways to prevent dehydration. So, of course, water is one and the appropriate intake of nutrients that provide you with water equivalent. So the ingestion of fruits. In the case of soups. Or other drinks, that provide some content of water, including milk.

 That's another way to add water to your body. Second is how do you prevent the evaporation of the loss of your normal waterstorage. So appropriate clothing, right? If, if it is, really cold, you know, use appropriate layers of clothing. If it's is hot then less amount of clothing. If you're going to do a physical activity, specifically exercise, wear the appropriate outfit or clothing to allow perspiration or to preserve, you know, the fluid, right? And then the adjustment of the room temperature is very important. I mean, it, you can get dehydrated if you spend all day in the sauna, right? Likewise, if you have the room temperature at a very high temptemperature, you can evaporate more of your fluid. It is important also to take care of what we call the mucosa, right? So another way to lose water, is just keeping your mouth open when you don't have to do that. So when you're running, and you keep your mouth open is another way to lose extra moisture, water, right?

So if you can breathe through your mouth when you're doing physical activity, it's probably a way to decrease the amount of water losses. I think those are some of the most,common ways. I would say also the people that swimming for a long period of time. One of the normal responses of the human body after swimming or after being immersed in water is to urinate.

So most people will leave the swimming pool to go and use the restroom. So if you are swimming or you are inside pool, the sea, or, anything like that, it's important when you get out after you control your body temperature and take care of the extra water or towel, whatever you're going to do, to drink the appropriate amount of fluid, water or supplement to prevent dehydration as well.

Host: And doctor, I'd love to talk about hydration supplements for a bit. How do those work? And with so many on the market, what should we look for in their ingredients?

Carlos Zayas, MD: The best hydration supplement by excellence is certainly water. Now, we can get, water intoxicated when we only drink water because we have to understand that the human body keeps a perfect balance between the content of water and the content of what we call the body electrolytes. And those are primarily sodium and chloride, which is salt and, but also potassium, calcium, magnesium, and phosphorus.

So. So let's say you eat a normal diet, you eat your three meals with snacks. You have, you're at work, and you're appropriately dressed in normal body temperature. With water alone, it should be enough, you know, to provide the amount of water losses that you have in your day-to-day activity.

But let's say that you go to the gym and you're going to do, let's say, an hour of exercise that is moderate, mild to moderate, but water would be another way to do it. Keep your joints and your muscles well-hydrated while you're doing exercise, and that seems to be enough for you. Now, if you are going to do an hour and a half of exercise that requires strenuous exercise, loss of perspiration, maybe going to the sauna, doing longrun, so speaking you might lose along with the normal water, excess electrolytes. So that's when drinks that contain electrolyte supplementation come to play, and it's important that they have the right balance of sodium, chloride and potassium as well as phosphorus. So, one thing that the public doesn't realize that is some of these supplemental drinks contain electrolytes, but they contain a lot of glucose. Sucrose or fructose. Now excess amount of sugar, will increase your blood sugar, which in fact will make you urinate more, and then it can dehydrate you on the other end.

So what I recommend is the appropriate amount of electrolytes, without much carbohydrate content in the drinks. So for instance, the World Health Organization would recommend that if you need to create your own home made, IV fluid for oral hydration, you take three tablespoons full of sugar and one of salt, and that will give you the appropriate relationship of glucose and sodium chloride.

Some of the best drinks out there, and I don't want to talk for brands, but, you know, any of the drinks that are zero or low calorie contain, adequate amount of potassium, sodium, and phosphorus without much glucose. And those seem to be the most appropriate for hydration after strenuous exercise. Another way to hydrate is, let's say you have aelderly person at home, who's taking diuretics. So these are drugs that make people produce urine or urinate, and at the same time, they lose electrolytes due to the effect of the drugs. So when they get dehydrated, they're not only needing water, they're needing also salt. So sometimes I recommend just a little bit of broth, or a small Campbell soup, chicken noodle soup or Lipton soup that contains enough sodium and water to replenish the needs, close to what we do in a hospital with one bag of what we call normal saline. So it depends on the characteristics of the patient or person, the type of activity he or she's doing, the body weight and also the health condition.

Host: What about if you're sick? Are hydration aids helpful then?

Carlos Zayas, MD: When we're sick, hydration is extremely important. Let's just take for example, viral illnesses. When we have the flu, when we have a cold, COVID, gastroenteritis or, you know, when people are sick of their stomach and all those will lead to dehydration in many ways. For example, when your body temperature goes up, you perspirate more, you lose a lot of water.

That's number one. When you have a fever, number two, you urinate more because the, what we call inflammatory molecules from your body fighting the infection or the virus, will make your kidneys filter more so you increase filtration, so you produce more urine so you lose more water. Also, when you have a fever, you tend to breathe faster.

So you, you move more air from your lungs, which is a very large area of exposure, so you lose extra water. So likewise, when you have stomach illness and you have loose stools, diarrhea, that kind of thing. Not only you don't eat as much, but you're losing extra water. So for all those conditions, it's important that you increase the amount of water, or fluid that you take, and I normally recommend that for every glass or bottle of water, you drink something else that is not water. I'll give an example. If you're going to drink the water, followed by a non-carbonated drink, let's say, milk, if you can tolerate milk, Gatorade, or Powerade or something along those lines that contain electrolytes or let's say broth or a homemade soup, that will give you not only the water component, but also a little bit of vitamins and electrolytes, sodium chloride, hopefully a little bit of potassium. You put potatoes in that and maybe carrots or spinach or something that will give you some phosphorus and magnesium, which are important electrolytes for muscle contraction and for the wellbeing of your heart and nerve conduction. So, water alone is sometimes not the most advisable thing to do. In addition to that, it's important to keep in mind that certain drinks can dehydrate you. I'll give an example.If you drink tea, sweet or unsweet, the presence of caffeine in the tea or the coffee acts like a diuretic. So you can actually get dehydrated drinking too much coffee, or tea. So if you're going to drink tea or coffee, then you have to double the amount of other fluids in order to compensate for what you're losing due to the caffeine component. Carbonated beverages as well, because of the fructose component. Fructose or any sugar will increase the filtration in kidneys, making you filter more water.

So if you drink a Coke. Then for every Coke, you need two glasses of water in order to compensate for what you're going to lose due to the caffeine and the Coke. So yeah, it gives you an idea that not all fluids are made equal.

Host: And wrap it up for us today, doctor. Can hydration supplements be harmful if overused or misused?

Carlos Zayas, MD: Yeah. Some of the commonly used hydration supplements can be harmful. And I'm going to give you some examples. People that only drink,Sport drinks all the time. They can actually increase the amount of glucose that they ingest per day, making their body weight go up, increasing body adiposity, keeping their blood sugar kind of elevated all the time, making their A1C go up and stay high for a long period of time.

Host: In that way, put you in this stage close to pre-diabetes in some instances. That's one. The other is some of these supplements might contain the, Iwould say incorrect proportion of electrolytes. Such an interesting conversation today, Doctor. Thank you so much for joining us and sharing that was Dr. Carlos Zayas. For more information, visit prismahealth.org/flourish. If you enjoyed this podcast, please share it on your social channels and explore our entire podcast library for topics of interest to you. I'm Caitlin Whyte and this is Flourish.

Thanks for listening.