text: my blood work results came back, can you help explain? what does these stand for and is it all that important for it  to be off a little? potassium was a tad high under cbc category:  mcv  - 1 pt low mch - 1 point lower than low end of range rdw - 2  higher  which letter would be my 'thyroid' count? these descirbe your rbc hemoglobin content.  the mcv (mean corpuscular volume) is basically saying "how much volume is in your reb blodd cells".  one of the main components of your rbcs is hemoglobin and, you need iron to make hemoglobin.  thus, a low mcv might mean that you are low on iron.  but, your rdw is a commnet to how acccurate the mcv is - the fact that it is high says that the mcv is essentially usuless as a diagnosic number.  the mch is another measure of hemoglobin in your rbc, but mds don't use this number much.  it's just given because it's a calcualted value from the other numbers given.  none of these numbers have anyhting to do with your throid.  although, the mcv can go up or down depending on your throid status.  but, again, the fact that the rdw is high negates it clinical value.  big picture: you are fine, if these are the only numbers that are off in your cbc.  if you are worried about your thyroid, get specific tests for them. all you really need is a tsh.