From the Guidelines
Having high red blood cell (RBC) count with low hemoglobin is an unusual combination that warrants immediate medical evaluation to determine the underlying cause and prevent potential complications. This condition could indicate several underlying issues such as dehydration causing artificially elevated RBC count while an iron deficiency or chronic disease is causing low hemoglobin 1. The most recent and highest quality study suggests that anemia in chronic kidney disease (CKD) is generally normocytic and normochromic, but microcytosis may reflect iron deficiency, aluminum excess, or certain hemoglobinopathies, while macrocytosis may be associated with vitamin B12 or folate deficiency 1.
Possible Causes and Implications
- Dehydration causing artificially elevated RBC count
- Iron deficiency or chronic disease causing low hemoglobin
- Microcytosis reflecting iron deficiency, aluminum excess, or certain hemoglobinopathies
- Macrocytosis associated with vitamin B12 or folate deficiency
- Anemia of CKD, which is generally normocytic and normochromic
Recommended Course of Action
You should consult with a healthcare provider who will likely order additional tests including a complete blood count, iron studies, vitamin B12 and folate levels, and possibly kidney function tests 1. While waiting for your appointment, stay well-hydrated and consider a balanced diet rich in iron (lean meats, beans, leafy greens) and vitamin C (which enhances iron absorption) 1. Avoid self-medicating with iron supplements before diagnosis as inappropriate supplementation can be harmful. This combination of lab values creates a paradox since RBCs typically carry hemoglobin, so when one is high and the other low, it suggests the RBCs may be smaller or contain less hemoglobin than normal, a condition that needs proper medical interpretation and treatment based on the underlying cause 1.
From the Research
Implications of Elevated Red Blood Cell (RBC) Count with Low Hemoglobin (Hb) Levels
- Elevated RBC count with low Hb levels can be an indicator of various health issues, including iron deficiency anemia 2 and anemia of chronic disease 3.
- Anemia of chronic disease is characterized by a reduced number of reticulocytes and reduced iron-binding capacity, and is often seen in patients with tumors 3.
- Iron deficiency anemia, on the other hand, is caused by decreased production of RBCs and is characterized by a reduction in either the hematocrit (Ht) or the concentration of Hb 2.
- Low Hb levels have been linked to an impaired quality of life and poor prognosis in patients with certain types of cancer, such as non-small cell lung cancer 3.
- Elevated RBC count with low Hb levels can also increase the risk of arterial ischemic stroke in children, particularly in those with large vessel and small vessel subtypes 4.
Diagnostic Considerations
- Measuring Hb and Ht levels alone may not be sufficient to diagnose iron deficiency anemia, as these levels can be normal even in individuals with iron depletion 2.
- A complete blood count (CBC) test should be accompanied by other tests of iron status, such as serum iron and ferritin, to pinpoint true iron deficiency 2.
- Abnormal RBC indices, such as high red cell distribution width (RDW) and low mean corpuscular volume (MCV), can increase the risk of arterial ischemic stroke in children 4.
Clinical Significance
- Maintaining Hb or Ht values around 11 g/dl or 33%, respectively, is important in critically ill patients to improve their chances of survival 5.
- The "critical" Hb or Ht level is an individual value, and a generally valid "transfusion trigger" does not exist 5.
- Patients over age 40 should not be subjected to Hb levels < 10 g/dl or < 30% without prior exclusion of silent myocardial ischemia (SMI) by appropriate investigations 5.