Is it possible to get high RBC in blood test due to fasting?

Question

Hello doctor,

I had a blood test done two months back and my RBC was 6.0, hemoglobin 17.2, and hematocrit 51, which were all high especially RBC. The blood test was in the morning and I had not eaten or drunk for eight hours before. I am an 18-year-old 130 lb male, and I was wondering if the blood test was high because I had fasting and it was in the morning. My doctor told me it might be polycythemia and to go back for another test in three months.

Answer 1

Hello,

Welcome to icliniq.com.

Dehydration for a prolonged duration can lead to a high RBC count, high hematocrit, and high hemoglobin levels. But eight-hour fasting cannot lead to such findings. It is advisable to repeat your test after a few days. Until then, keep yourself well-hydrated with lots of water. If still, it comes high after a few days, then further workup for polycythemia should be done in the form of EPO estimation, chest X-ray, EKG, and JAK2 mutation testing as per need.