Evidence-Based Supplement & Herb Guides

Lactoferrin Test: Gut Inflammation, Infection, IBD, and High Levels

Learn what a high fecal lactoferrin test means, how it detects gut neutrophil inflammation, and how clinicians distinguish IBD, infection, and noninflammatory bowel symptoms.

A fecal lactoferrin test measures an iron-binding protein released mainly by activated neutrophils in the digestive tract. When these white blood cells enter the...

Neutrophil Count Test: High Levels, Infection, Inflammation, and Immune Response

Understand a high neutrophil count, including ANC, infection and inflammation patterns, steroid and stress effects, left shift, and signs that need further blood evaluation.

A neutrophil count test measures the most abundant type of white blood cell in most adults. Neutrophils are rapid-response immune cells that leave the...

Neutrophil-to-Lymphocyte Ratio (NLR) Test: Inflammation, Immune Stress, High Ratio, and Meaning

Understand what the neutrophil-to-lymphocyte ratio means, why NLR may be high, how inflammation and immune stress affect it, and why context matters.

The neutrophil-to-lymphocyte ratio (NLR) is a calculated value from a complete blood count with differential. It compares two white blood cell populations: neutrophils, which...

Plasma Viscosity Test: High Levels, Inflammation, Blood Thickness, and Meaning

Learn what a plasma viscosity test measures, why levels may be high, how it compares with CRP and ESR, and when “thick blood” may signal an emergency.

A plasma viscosity test measures how strongly the liquid portion of blood resists flow. The result is influenced mainly by proteins dissolved in plasma,...

Platelet-to-Lymphocyte Ratio (PLR) Test: Inflammation, Immune Balance, High Ratio, and Meaning

Understand how the platelet-to-lymphocyte ratio is calculated, what a high PLR may mean, why cutoffs vary, and how inflammation and immune changes affect it.

The platelet-to-lymphocyte ratio (PLR) is calculated from two components of a complete blood count: the platelet count and the absolute lymphocyte count. Platelets help...

Procalcitonin Test: Bacterial Infection, Sepsis Risk, High Levels, and Interpretation

Learn how the procalcitonin test supports bacterial infection and sepsis assessment, what high and low levels mean, and how trends can guide antibiotics.

A procalcitonin (PCT) test measures a protein in blood that often rises during a significant systemic bacterial infection. Healthy people usually have very low...

Serum Amyloid A (SAA) Test: Acute Inflammation, High Levels, and Disease Activity

Learn what a serum amyloid A test measures, why SAA rises in acute inflammation, how it tracks disease activity, and when persistent elevation raises AA amyloidosis concern.

Serum amyloid A (SAA) is a group of acute-phase proteins that can rise sharply when the body responds to infection, tissue injury, or inflammatory...

White Blood Cell (WBC) Count Test: High Levels, Infection, Inflammation, and Causes

Understand what a WBC count measures, why white blood cells rise with infection, inflammation, stress, medicines, or blood disorders, and how results are evaluated.

A white blood cell (WBC) count measures the total number of leukocytes circulating in a blood sample. These immune cells help identify and respond...

Activated T-Cell Marker Test: HLA-DR, CD38, Immune Activation, and Inflammation

Learn how HLA-DR and CD38 flow cytometry measures activated T cells, what high results may mean, why ranges vary, and how clinicians plan follow-up.

An activated T-cell marker test uses flow cytometry to estimate how many T lymphocytes are showing signs of recent or ongoing stimulation. Laboratories may...

B-Cell Count Test: CD19, CD20, Immune Function, and Antibody Production

Understand how CD19 and CD20 B-cell counts are measured, why results may be high or low, how anti-CD20 therapy affects them, and which follow-up tests assess antibody function.

A B-cell count test measures the number and percentage of B lymphocytes in blood, usually by flow cytometry. Laboratories most often identify B cells...

CD4 Count Test: Helper T Cells, Immune Function, HIV Monitoring, and Meaning

Learn what a CD4 count measures, how HIV affects helper T cells, what common ranges and thresholds mean, why results fluctuate, and how the test guides monitoring and infection prevention.

A CD4 count measures helper T cells, a group of lymphocytes that coordinate immune responses against infections and support B cells, macrophages, and cytotoxic...

CD4/CD8 Ratio Test: Immune Balance, High and Low Ratio, and Meaning

Learn how the CD4/CD8 ratio is calculated, what low or high results may mean, why an inverted ratio is nonspecific, and how the test adds context in HIV and immune monitoring.

The CD4/CD8 ratio compares helper T cells with cytotoxic T cells in a blood sample. It is calculated by dividing the absolute CD4 count...

CD8 Count Test: Cytotoxic T Cells, Immune Function, and Viral Response

Learn what a CD8 count measures, why cytotoxic T-cell numbers may rise or fall, how viral infections affect results, and why cell quantity does not equal antiviral function.

A CD8 count measures a major group of T lymphocytes involved in recognizing and removing virus-infected, damaged, or abnormal cells. The cells are often...

Chemokine Panel Test: Immune Signaling, Inflammation, and Cell Migration Markers

Understand what a chemokine panel measures, why immune-signaling and cell-migration markers rise or fall, and how specialists interpret patterns and limitations.

A chemokine panel measures several small immune-signaling proteins that help direct white blood cells toward infection, injury, tumors, or inflamed tissue. Unlike a routine...

Cytokine Panel Test: IL-1, IL-6, IL-8, TNF-Alpha, Interferon-Gamma, and Immune Activation

Learn what a cytokine panel measures, how IL-1, IL-6, IL-8, TNF-alpha, and interferon-gamma patterns are interpreted, and why results require clinical context.

A cytokine panel measures a group of proteins that immune and tissue cells use to communicate. Common targets include interleukin-1 beta, interleukin-6, interleukin-8, tumor...

Cytokine Storm Blood Test Panel: IL-6, Ferritin, CRP, D-Dimer, and Severe Inflammation

Understand how IL-6, ferritin, CRP, D-dimer, blood counts, and clotting tests help evaluate cytokine storm, CRS, HLH, MAS, and severe inflammation.

A “cytokine storm blood test panel” is not one standardized laboratory test. It is a group of tests used to look for severe, dysregulated...