A high red blood cell count is known as erythrocytosis or polycythemia. Anxiety is a normal stress response, but when it is excessive or persistent, it can trigger physical symptoms like a rapid heart rate. Erythrocytosis refers to an elevated concentration of red blood cells in the bloodstream, typically measured through a common blood test. When a routine lab test shows an elevated red blood cell count in a person experiencing high stress, it is natural to wonder if the psychological state is the direct cause. This article explores the biological relationship between chronic anxiety and an elevated red blood cell reading.
The Direct Answer: Anxiety and Red Blood Cell Production
Psychological stress and anxiety do not directly stimulate the bone marrow to create new red blood cells, a process called erythropoiesis. The body tightly regulates red blood cell production to maintain a specific oxygen-carrying capacity. This regulation is primarily managed by the hormone erythropoietin (EPO), which is largely produced by the kidneys.
EPO is released in response to decreased oxygen levels in the blood, a state known as hypoxia. When oxygen delivery to the tissues is low, EPO signals the bone marrow to accelerate red blood cell production. Since anxiety does not cause chronic, systemic low oxygen, it does not trigger the EPO mechanism that would result in a true increase in the body’s total red blood cell mass.
Understanding the Apparent Link: Hemoconcentration
The most plausible link between anxiety and an elevated red blood cell reading is a temporary phenomenon called hemoconcentration. Hemoconcentration occurs when the fluid portion of the blood, known as plasma, is reduced. This causes the remaining cellular components to become more concentrated, creating an “apparent erythrocytosis.” The total number of red blood cells remains the same, but the ratio of cells to fluid volume is temporarily higher.
Acute anxiety or panic attacks can contribute to this fluid shift. Physical manifestations of anxiety, such as excessive sweating or hyperventilation, can lead to subtle fluid loss. Additionally, individuals experiencing high levels of acute stress may neglect proper hydration, which further decreases plasma volume.
When a blood sample is drawn during dehydration or acute stress, the laboratory measurement of hematocrit—the volume percentage of red blood cells in the blood—will be inaccurately high. This relative increase is not a true indication of a disease process involving overproduction. Once proper hydration is restored, the plasma volume returns to normal, and a subsequent blood test will typically show a normal red blood cell count.
Primary Medical Causes of Elevated Red Blood Cells
Since anxiety is rarely the underlying cause of a persistent high red blood cell count, any long-term elevation warrants investigation into other medical conditions. Elevated counts are broadly categorized into primary and secondary erythrocytosis, based on whether the cause originates within the bone marrow or is a response to an external factor.
Primary Erythrocytosis
Primary polycythemia, most commonly known as Polycythemia Vera (PV), is a rare disorder originating in the bone marrow. In PV, a mutation in the JAK2 gene causes the bone marrow to produce red blood cells in an uncontrolled manner, independent of the body’s EPO signals. This disease is an acquired condition.
Secondary Erythrocytosis
Secondary erythrocytosis is far more common and occurs when the body produces too many red blood cells in response to chronic hypoxia. The body attempts to compensate for a lack of oxygen by increasing the number of oxygen-carrying cells. Common causes include chronic lung diseases like emphysema or Chronic Obstructive Pulmonary Disease (COPD), which limit oxygen absorption.
Other external factors that create chronic low oxygen states include:
- Severe obstructive sleep apnea.
- Heavy tobacco smoking, which can lead to carbon monoxide exposure.
- Living at high altitudes, where the air naturally contains less oxygen.
- Certain tumors of the kidney or liver that inappropriately secrete EPO.
When to Seek Medical Guidance
Any finding of a persistently elevated red blood cell count needs medical evaluation by a healthcare provider. While temporary effects of stress or dehydration can explain a single high reading, a physical examination and diagnostic testing are required to differentiate between a relative increase and a true absolute increase in red cell mass. The initial evaluation often includes a careful review of symptoms, a detailed assessment of lifestyle factors, and specific blood tests, including a measurement of erythropoietin levels.
It is helpful to inform your doctor about any anxiety symptoms you are experiencing, as this provides context for potential hemoconcentration. However, the medical focus must remain on ruling out serious underlying conditions such as lung disease, sleep disorders, or the intrinsic bone marrow disorder, Polycythemia Vera. Addressing the root cause is the only way to manage a true elevation and prevent potential complications associated with thickened blood.