High Hemoglobin/ hematocrit & dehydration????

[Nomad]

For at least a year or two, every time I get a CBC, which is often in my case due to low platelets, my hemoglobin and hematocrit are a little high. They ALWAYS tell me that I must be dehydrated.  At first, I just let it go, but NOW I'm starting to wonder about it.
For one thing, since it's very hard to draw my blood, I drink a crazy amount of water prior to the test. The day before I drink extra water and the morning of the test, I drink a ridiculous amount of water. I drink so much water, that I need to use the facilities several times before leaving the house, immediately upon going to the testing lab and if they don't take me immediately, I'll need to use it again, and then immediately after my blood is drawn and if I don't go immediately home, I'll have to use it again wherever I go. I drink an absurd amount of water because I'm sick and tired of the tech saying "DID YOU DRINK WATER?" Well, yes, I drank a freakish amount of water.  So, I doubt I am truly dehydrated. What the heck is hemoglobin and hematocrit and are they commonly elevated with Sj. Syndrome? What might this mean? And are people with Sj. Syndrome commonly dehydrated?

[SjoGirl]

Hemaglobin is what carries oxygen to your blood.

Hematocrit is explained here:  http://www.mayoclinic.org/tests-procedures/hematocrit/details/why-its-done/icc-20205465

I am not a doc, but wonder if it's possible to be dehydrated from drinking too much. If you are going to the bathroom that much you maybe flushing your system. I do know that in the past when I drink to much I end up with low sodium levels because I'm excreting it.

I have learned that not all readings are ones to be concerned about, a huge imbalance in readings yes, more minor ones typically no. In fact, I've had docs tell me that my readings may just be normal for me.

[bartolo]

You know you are dehydrated when:
- Your urine has a strong yellow color (not just pale yellow).
- Your body weight is lower than your usual weight. It's very simple: if you miss 2 liters of water you will be 2 kilograms lighter.
- You have dry mouth (you can have dry mouth from Sjogrens and you can be perfectly hydrated, though).
- When you pinch the skin on the back of the hand and it does not recoil immediately, it means you are probably dehydrated (unless your skin is loose like that all the time).

If you drink so much before the tests, it's very unlikely you are dehydrated at the time of the test.

Drinking a lot of water does not dehydrate you and does not flush water out of you. Of course, drinking a lot will make you urinate a lot, because your kidneys want to get rid of excess of water. Dehydration means lack of water in your body.

If a doctor says to you "you must be dehydrated" then he has to prove this to you there and then. Slightly elevated hemoglobin and hematocrit may be normal, but if you are concerned, ask a doctor for explanation (other than "dehydration").

[Linda196]

As with many blood tests, hemoglobin and hematocrit on their own don't tell a complete story.

Hemoglobin (Hgb) is a component of red blood cells, and if elevated, you have to look at the total count of red cells as well. Different diagnoses are based on whether the cell count is elevated, or a normal cell count is carrying excessive Hgb.

Hematocrit is the ratio of the volume of red blood cells to total blood volume. If the number of red cells is normal, and the ratio is high, that is an indicator of dehydration, but if the number of cells is low or high, that would require further investigation, for either anemia or polycythemia (excessive red cells). That's why the reason for the elevated Hgb needs to be determined before a blanket "dehydration" statement is used.

Some chronic conditions can cause increased red blood cells and corresponding increased Hgb, although I've never heard Sjogren's in that list. It usually means chronic heart, lung or kidney disease, where the body tries to compensate for deficiencies in other organs by improving the blood's ability to carry oxygen to needy organs.

[jazzlover]

Dehydration is related to ADH .. if you are truly dehydrated. You could have them test your aldosterone levels.