Hematologist is the expert on blood disorders

Ask Dr. Keith Roach M.D

Hematologist is the expert on blood disorders

DEAR DR. ROACH: Recent blood tests have left me perplexed. My hemoglobin, hematocrit and MCV were slightly high. What might be the underlying cause of these elevations? What do hemoglobin, hematocrit and MCV refer to? Also, my hematocrit and MCV levels were high on the previous blood test, about a year ago. Now the hemoglobin seems headed in the same direction. I am worried about cancer.

I have been healthy for most of my life, as a non-smoker, non-drug user. I do not live at high altitude. — R.Z.

ANSWER: Hemoglobin is the major protein in red blood cells, used to transport oxygen from the lungs to all the tissues and cells of the body that need it. Hematocrit is the proportion of blood comprised of red blood cells (the rest is plasma, with negligible contributions of white blood cells and platelets, normally). The mean corpuscular volume, MCV, is a measure of the average size of a red blood cell.

All of these are slightly above normal in you, which should raise the concern of polycythemia (rubra) vera (which literally means 'too many red blood cells'). Polycythemia vera is a myeloproliferative disorder, a disease of the bone marrow, but not a cancer. However, there are several other possibilities, which may need evaluation.

Your levels have been high twice, a year apart, so I do think you should be evaluated for the cause. Low blood oxygen from smoking or from altitude can be ruled out from the information you gave me. However, other heart or lung diseases, sleep apnea and carbon monoxide poisoning (much more common than you might think in winter months) can be quickly evaluated by a careful exam and by measuring blood oxygen and carbon monoxide levels. There are tumors that can secrete a hormone called erythropoietin, which increases bone marrow production of red blood cells, so that should be checked.

Polycythemia vera usually has high white blood cell and platelet cell counts and a low MCV, so it is less likely in you.

Given how well you feel, and how subtle the elevations are, I think it's possible that you have no disease at all. These levels may be normal for you. However, get evaluated. A hematologist is the expert in these conditions.

DEAR DR. ROACH: I am on a proton pump inhibitor, which was prescribed by my doctor several months ago after complaining of symptoms relating to GERD. While the medication has improved most of the symptoms, once in a while I still experience a slight burning sensation in my lower chest. Are PPIs designed to totally relieve the symptoms of GERD, or is it common to still have occasional chest discomfort? (I have had tests to rule out heart-related problems, which I am aware can cause the same sort of symptoms.) Also, if the problem is caused by the lower sphincter valve in the esophagus not functioning correctly, how does a PPI remedy that? — Anon.

ANSWER: Proton pump inhibitors do not stop gastroesophageal reflux, which literally means 'the backward passage of stomach contents into the esophagus.' By reducing the ability of the stomach to make acid, the damage to the esophagus can be minimized and symptoms improved, though often not totally relieved. Metoclopramide does reduce the actual reflux of material, but has such dangerous side effects that it is seldom used long term. PPIs have their own risk of long-term side effects, so I recommend trying to slowly taper off the medication after six weeks or so. *** Dr. Roach regrets that he is u nable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell. edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, FL 32803. Health newsletters may be ordered from www.rbmamall.com.