What are the causes of decrease ESR?

A decreased ESR (Erythrocyte Sedimentation Rate) can occur due to various physiological and pathological conditions. Here’s a concise overview:

🔽 Causes of Decreased ESR

🧬 Blood-related Conditions
– Polycythemia vera: Increased number of red blood cells slows sedimentation
– Sickle cell disease: Abnormal RBC shape prevents stacking (rouleaux formation)
– Hereditary spherocytosis: Spherical RBCs resist sedimentation
– Acanthocytosis: Spiked RBC membranes disrupt settling

🧫 Protein & Plasma Abnormalities
– Hypofibrinogenemia: Low fibrinogen reduces RBC aggregation
– Hypogammaglobulinemia: Low immunoglobulin levels affect plasma viscosity
– Hyperviscosity syndrome: Thick plasma slows RBC movement

❤️ Cardiovascular & Systemic Conditions
– Congestive heart failure: Alters blood flow and plasma composition
– Liver disease: Affects plasma protein synthesis

💊 Medications
– NSAIDs (e.g., aspirin, ibuprofen)
– Corticosteroids
– Antibiotics and immunosuppressants (e.g., penicillamine, quinine)

🚬 Lifestyle Factors
– Smoking
– High-dose aspirin therapy
– Certain dietary patterns

🧪 Clinical Note
A low ESR is usually not a cause for concern on its own. However, it may help identify underlying conditions when interpreted alongside other tests.