Lab Tests Reference Library

Hemoglobin is the protein in red blood cells that carries oxygen throughout the body. It is the primary test for diagnosing anemia.

RBC count measures the number of red blood cells per volume of blood. Low RBC indicates anemia; high RBC (polycythemia) can suggest dehydration or bone marrow disorders.

WBC count measures the total number of white blood cells (leukocytes). Elevated WBC suggests infection or inflammation; low WBC may indicate bone marrow suppression.

Platelets (thrombocytes) are cell fragments essential for blood clotting. Low platelets (thrombocytopenia) cause bleeding risk; high platelets may suggest inflammation or clotting risk.

Hematocrit (packed cell volume) is the percentage of blood volume occupied by red blood cells. It reflects the overall red cell mass.

MCV measures the average size of red blood cells. Low MCV (microcytic) suggests iron deficiency or thalassemia; high MCV (macrocytic) suggests B12/folate deficiency.

MCH measures the average amount of hemoglobin per red blood cell. Low MCH indicates hypochromic (pale) red cells, typical of iron deficiency.

MCHC measures the average concentration of hemoglobin in red blood cells. Low MCHC confirms hypochromic anemia; high MCHC can suggest hereditary spherocytosis.

RDW measures the variation in red blood cell size (anisocytosis). Elevated RDW is an early marker of iron deficiency anemia and helps differentiate anemia types.

Neutrophils are the most abundant white blood cells and the first responders to bacterial infections. Elevated neutrophils suggest bacterial infection or stress; low levels (neutropenia) increase infection risk.

Lymphocytes are white blood cells critical for immune response. Elevated lymphocytes suggest viral infection; lymphocytopenia may indicate immune deficiency or steroid use.

Monocytes are white blood cells that mature into macrophages and dendritic cells. Elevated monocytes may suggest chronic infection, autoimmune disease, or inflammatory conditions.

Eosinophils fight parasites and participate in allergic reactions. Elevated eosinophils (eosinophilia) suggest allergies, asthma, or parasitic infections.

Basophils are the rarest white blood cells, involved in allergic reactions and inflammation. Elevated basophils may suggest allergic disease or myeloproliferative disorders.

ESR measures how quickly red blood cells settle in a test tube. It is a non-specific marker of inflammation and infection. Elevated ESR suggests ongoing inflammation.

CRP is a protein produced by the liver in response to inflammation. It rises rapidly during infection or inflammatory states. High-sensitivity CRP (hs-CRP) assesses cardiovascular risk.

PT measures how long it takes blood to clot via the extrinsic pathway. INR standardizes PT results globally. Used to monitor warfarin therapy and assess liver function.

aPTT measures clotting via the intrinsic pathway. Used to monitor heparin therapy and detect clotting factor deficiencies. Prolonged aPTT suggests coagulation disorders.