From the Guidelines
The medical term for a mild elevation of hemoglobin and hematocrit (H and H) is polycythemia or erythrocytosis. This condition occurs when there is an increase in the number of red blood cells in the bloodstream, resulting in higher than normal hemoglobin and hematocrit levels. Mild elevations are often relative or secondary polycythemia, which can be caused by dehydration, smoking, living at high altitude, or as a compensatory response to chronic hypoxia from conditions like COPD or sleep apnea 1. It can also be caused by certain medications like testosterone or erythropoietin.
Causes and Management
Management typically involves addressing the underlying cause rather than specific medication. If dehydration is the cause, increasing fluid intake is recommended. For smokers, smoking cessation is advised. In cases where the elevation is due to a medical condition, treating that condition is the priority. Regular monitoring of H and H levels is important to ensure they don't continue to rise, as significant elevations can increase blood viscosity and the risk of thrombotic events. Iron deficiency is frequently encountered in cyanotic individuals and requires assessment of serum iron, ferritin, and transferrin levels 1.
Key Considerations
- Iron deficiency can contribute to symptoms and compromise systemic oxygen transport without lowering viscosity, and its treatment with iron supplementation until iron stores are replete can be done safely 1.
- Therapeutic phlebotomy may be indicated in cases of hemoglobin greater than 20 g per dL and hematocrit greater than 65%, associated with headache, increasing fatigue, or other symptoms of hyperviscosity in the absence of dehydration or anemia 1.
- Regular monitoring of H and H levels is crucial to prevent significant elevations that can increase blood viscosity and the risk of thrombotic events.
Given the most recent and highest quality study available 1, the management of mild elevation of hemoglobin and hematocrit should prioritize addressing the underlying cause, monitoring for iron deficiency, and considering therapeutic phlebotomy only when necessary, to minimize the risk of thrombotic events and ensure optimal patient outcomes.
From the Research
Definition of Polycythemia
The medical term for mild elevation of Hemoglobin (H) and Hematocrit (H) is polycythemia. Polycythemia is a condition characterized by an increased concentration of hemoglobin and hematocrit in the blood [ 2, 3, 4, 5, 6 ].
Types of Polycythemia
There are two main types of polycythemia:
- Primary polycythemia, also known as polycythemia vera (PV), which is a myeloproliferative neoplasm [ 3, 4 ]
- Secondary polycythemia, which is caused by excess erythropoietin (EPO) or decreased plasma volume [ 4, 5 ]
Diagnosis of Polycythemia
The diagnosis of polycythemia is based on the presence of elevated hemoglobin and hematocrit levels, as well as other clinical and laboratory findings, such as:
- Elevated serum EPO levels [ 3 ]
- Presence of JAK2 mutations [ 3, 4 ]
- Splenomegaly [ 4, 5 ]
- Thromboembolic events [ 2, 4 ]
Key Points
Some key points to note about polycythemia include: