Dehydration
Hi,
I have had to deal with dehydration almost every working day for 30 or 40 years. Why? Because I fit contact lenses. Unless you are hydrated, you probably cannot wear contact lenses.
CL is a misnomer. Unless a contact lens is a horrible misfit or you are dehydrated, the lens does not touch the eye...It floats in a pool. The pool has to be large enough to float the lenses. I will give a ridiculous analogy: You cannot float a battleship in a pool.
When you are dehydrated all fluids in your body are reduced---your tear volume is low and viscous, your saliva volume is low and viscous, your urine is probably dark in color.
I will expand on this. You may feel like you have too many tears because the tears are so viscous that they cannot drain through your drainage system properly; they spill over your lids. However, reality is that you do not have enough tears---you just have tears that cannot drain properly. (Analogy: You have two sinks with stoppers removed. You pour water into one and honey into the other at the same rate. The honey sink flows over the top because the fluid cannot drain fast enough. The water sink drains properly. Remember the fluid was going into each sink at the same rate.) You may feel as though you have too much saliva because it is so viscous that it does not drain down your throat properly so there is more fluid in your mouth (usually thick and gooey). Dark urine is very frequently a sign of dehydration---however this is not always true. Light color urine is frequently a sign that you are hydrated: however not always.
Many things can make you dehydrated:
1) Not drinking enough water (big surprise here).
According to the nutritionists the water intake should equal or exceed: Take your body weight (how much you weigh) and divide it by two. Example: If you weigh 200 pounds---you divide it by two. That gives you an answer of 100. A 200 pound person should drink 100 ounces of water (You cannot count soft drinks, orange juice, electrolyte drinks, milk,etc. You count only water) each day.
2) Excess caffeine (coffee, tea, etc.). There are a bunch of studies going on at present about the proper amount of caffeine to consume. There is quite a bit of conflicting data on this (probably caused by whoever is paying for the study). My guess from what I have read is: You probably want to consume 135mg to 300mg of caffeine per day. 135mg is probably a typical 8oz mug of coffee in a cafe.
There have been studies that show you are more apt to get Altzheimer's or Parkinson's if you consume NO caffeine. I am not sure how valid the studies were. I saw only the results given to the general public. I did not see the original data.
If you consume too much caffeine, the fact that it is a diuretic really starts to be a factor. Years ago, when I took nutrition classes, they considered 6 cups of coffee absolute red-line. When you consume a diuretic, the water you consume tends to go through your system without you getting as much much use out of it. The greater the amount of caffeine, the less use the water is to your body.
3) Excess sugar tends to thicken the solutions in the body. This reduces the use the body can make of water that is consumed.
Most energy drinks, soft drinks, Gatoraid type drinks, etc. tend to contain a lot of carbohydrate (sugars and starches). Electrolytic drinks and similar are a very good thing up to a certain point. Then you hit the negative effects of the sugars and the very good electrolyte, etc. type drink becomes a negative factor instead. Like most things in life, Think Moderation.
4) Alcohol tends to have the same general effect on the body as a combination of diuretic and excess sugar. Think about this: Two guys are out mowing their lawns (push, not powered mowers). One of them is drinking beer and the other is having water. Guess which one is sweating the most fluids out of his system and which one is retaining the most fluid.
5) Many medications tend to dehydrate. If you are taking anything for allergies, sinus, nasal drip and similar, be suspicious that they may be dehydrating. If your med says to drink a lot of water there is a good chance it is dehydrating. Ask your physician if any of your meds tend to make you dry.
Re Potassium: Personal experience: My physician has told me that my potassium is too high and to stop eating bananas and stop nutrition drinks that contain potassium. The reason is that excess potassium makes a person more prone to heart attacks. This is a sample of one person. One is not a good number for statistics. However, if you are consuming potassium in drinks, pills or bananas, you should probably ask your M.D. what your potassium level was at your last physical. He/She can tell you if it is too high.
Enjoy,
Jim
ps My last nutrition class was many years ago.