Immunity

SII

SII integrates three immune compartments — platelets (thromboinflammation), neutrophils (innate activation), and lymphocytes (adaptive capacity) — into a single index.

What it is

SII integrates three immune compartments — platelets (thromboinflammation), neutrophils (innate activation), and lymphocytes (adaptive capacity) — into a single index. Elevated SII is linked to higher cardiovascular mortality, cancer incidence, and accelerated biological aging in large cohort studies.

What affects your levels

Same drivers as NLR/PLR combined: chronic stress, obesity, autoimmune disease, smoking, malignancy, infection, corticosteroids.

Signs and symptoms

Asymptomatic. Very high values reflect severe immunoinflammatory dysregulation that may co-occur with fatigue, recurrent infection, or slow recovery.

Foods that help

See NLR. Comprehensive anti-inflammatory lifestyle: Mediterranean diet, omega-3, adequate sleep, stress management, regular exercise.

Foods to limit

See NLR.

Educational information only — not a diagnosis. Every Pheno result is interpreted in context and reviewed by a physician.

See all 119 markers we test →