What are the signs and symptoms of polycythemia?

Signs and Symptoms of Polycythemia

Polycythemia presents with a constellation of symptoms related to hyperviscosity, thrombosis risk, and myeloproliferation, including pruritus (33%), erythromelalgia (5.3%), transient visual changes (14%), and splenomegaly (36%), with thrombotic and hemorrhagic complications representing the most life-threatening manifestations. 1

Hematologic Manifestations

Elevated blood cell counts are the hallmark laboratory findings:

• Erythrocytosis (hemoglobin >16.5 g/dL in men or >16.0 g/dL in women) is the required diagnostic criterion 1
• Thrombocytosis occurs in 53% of patients 1
• Leukocytosis is present in 49% of cases and represents a PV-related feature that strengthens diagnostic suspicion 2, 1
• Elevated hematocrit exceeding the 95th percentile for normal distribution meets criteria for suspected polycythemia vera 2

Vascular and Thrombotic Symptoms

Thrombosis is the major cause of morbidity and mortality:

• Arterial thrombosis occurs in 16% of patients prior to or at diagnosis 1
• Venous thrombotic events occur in 7%, potentially involving unusual sites such as splanchnic veins 1
• Transient visual changes affect 14% of patients, reflecting microvascular occlusion 1
• During the pre-phlebotomy era, thrombosis was the major cause of death with median life expectancy less than 2 years 3

Microcirculatory and Hyperviscosity Symptoms

Symptoms related to increased blood viscosity and microvascular occlusion:

• Pruritus (itching) affects 33% of patients, often aquagenic (triggered by water exposure) 1, 4
• Erythromelalgia (burning pain in extremities with redness) occurs in 5.3% 1, 4
• Headaches and dizziness result from hyperviscosity 4
• Fatigue is a prominent constitutional symptom 4

Physical Examination Findings

Splenomegaly is present in 36% of patients with associated abdominal discomfort 1, 4

Plethoric appearance (ruddy, reddish complexion) reflects increased red blood cell mass 5

Hemorrhagic Complications

Bleeding risk is paradoxically increased despite thrombocytosis:

• Acquired von Willebrand disease can occur with extreme thrombocytosis (platelet count ≥1000 × 10⁹/L) 1
• Bleeding manifestations include epistaxis, easy bruising, and gastrointestinal bleeding 6

Constitutional Symptoms

Systemic symptoms affecting quality of life:

• Bone pain from marrow hyperplasia 4
• Night sweats 4
• Weight loss in some patients 4
• Chronic fatigue despite adequate sleep, particularly when secondary to sleep apnea 7

Secondary Polycythemia Presentations

When polycythemia is secondary to hypoxemia:

• Symptoms of underlying condition predominate (e.g., sleep apnea with obesity, chronic lung disease) 3, 7
• Mild elevation in hemoglobin (less than 18.5 g/dL in men) is more typical of secondary causes than polycythemia vera 7
• Patients with sleep apnea may report chronic fatigue and be unaware of sleep fragmentation 7

Critical Pitfalls to Recognize

Do not assume "adequate sleep" rules out sleep apnea as a secondary cause—patients with obstructive sleep apnea are typically unaware of their sleep fragmentation and nocturnal arousals 7

Distinguish primary from secondary polycythemia by checking serum erythropoietin levels: low EPO (<2.9 mU/mL) with specificity >90% is highly suggestive of polycythemia vera, while elevated or high-normal EPO suggests secondary causes 2, 8

Major symptoms in polycythemia rubra vera relate to arterial hypertension and arterial/venous thrombosis, and strokes may be the first manifestation 3