A routine blood test provides insights into your body’s health. Among its measurements, “polys” indicate immune system activity. Understanding what high or low levels of these cells signify can reveal important information about your health.
What Are Polys
“Polys” refers to polymorphonuclear leukocytes, also known as neutrophils. These primary white blood cells are a significant part of your innate immune system. Neutrophils act as first responders, swiftly migrating to sites of infection or inflammation to combat invading pathogens like bacteria and fungi.
Produced in the bone marrow, these cells are released into the bloodstream, where they circulate for a short period, typically less than 24 hours. Their main function is to engulf and destroy harmful microorganisms through phagocytosis. Neutrophils also release antimicrobial proteins and form web-like structures called neutrophil extracellular traps (NETs) to ensnare pathogens.
Understanding Your Polys Count
Neutrophil levels are measured as part of a complete blood count (CBC) with differential. This test determines the number of each white blood cell type, including neutrophils, in your blood. Results are usually reported as an absolute neutrophil count (ANC) or as a percentage of total white blood cells.
A normal neutrophil count generally ranges between 2,500 and 7,000 neutrophils per microliter of blood, though these ranges can vary slightly between different laboratories. The differential part of the CBC also indicates the proportion of segmented (mature) and band (immature) neutrophils. Deviations from this range indicate your body is responding to an internal change.
Why Polys Might Be High
An elevated polys count, known as neutrophilia, often signals that your body is actively fighting something. The most frequent reason for high neutrophils is a bacterial infection, such as pneumonia or appendicitis. The body rapidly produces and releases more neutrophils to combat the threat, rushing to the infection site to neutralize pathogens.
Inflammation from conditions like autoimmune diseases (e.g., rheumatoid arthritis or inflammatory bowel disease) can also cause neutrophilia. Physical or emotional stress can temporarily increase neutrophil levels. Certain medications, including corticosteroids and lithium, are known to raise neutrophil counts. Less commonly, some blood disorders or cancers, such as chronic myelogenous leukemia, can lead to persistently high neutrophil levels due to abnormal cell production.
Why Polys Might Be Low
A low polys count, termed neutropenia, indicates a compromised immune system, making the body more susceptible to infections. Viral infections, such as influenza, hepatitis, or HIV, are common causes, as they can temporarily suppress bone marrow activity. Severe bacterial infections can also overwhelm the bone marrow, depleting neutrophils.
Certain medications frequently cause neutropenia, notably chemotherapy drugs. Other drugs, like some antibiotics or anti-inflammatory medications, can also reduce neutrophil levels. Autoimmune diseases, such as lupus or rheumatoid arthritis, can cause the immune system to mistakenly attack healthy neutrophils. Problems with the bone marrow, like aplastic anemia or myelodysplastic syndromes, directly impair neutrophil production. Additionally, nutritional deficiencies can affect bone marrow function and lead to low neutrophil counts.
Next Steps and Medical Advice
Blood test results, including your polys count, are one piece of a comprehensive health assessment. A healthcare professional must interpret these results within the context of your medical history, current symptoms, and other diagnostic findings. Self-diagnosis based solely on blood test numbers is not advisable.
An abnormal polys count indicates that further investigation may be needed to determine the underlying cause. Your doctor can assess whether additional tests or treatments are necessary. Discussing your results thoroughly with your healthcare provider ensures an accurate diagnosis and appropriate management plan for your specific situation.