low ferritin + normal iron = immune problems?
I just recently found out (by accident, actually) that I have low ferritin (serum count was 4 ng/mL). However, all other blood tests are normal: normal hemoglobin, hematocrit, iron, etc. I'm a 27-year-old male.
I'm sick. I guess I'm really just "under the weather." You know how your body tells you that you are coming down with a cold or flu? Sometimes a slight headache, sometimes a runny nose, sometimes a sore throat for a few hours, maybe a sore inside your nose or mouth, loss of mental clarity, and a general feeling of lousiness.
I've felt like that for at least 3-4 years, during which time I've caught every cold and flu (which has lingered and kept me sick for weeks each occurrance). And I got mumps last winter. That was fun.
I'm also excessively tired. I sleep a lot. Any strenuous physical activity wears me out very quickly. And when I exercise, my muscles and joints are sore for days.
I'm wondering if anyone else has impaired immunity coupled with very low ferritin, or any other thoughts as to what might be causing this?