Sepsis has a number of biomarkers, or measurable substances within the body, that medical professionals use to diagnosis and treat sepsis. Lactate levels are an important biomarker for sepsis and are included in the treatment bundles for sepsis. Other biomarkers that a medical team might look for when diagnosing and treating sepsis include pro-inflammatory cytokines, C-reactive protein (created by the body to fight infection), or monocyte activation.

Biomarkers are measured for aid in diagnosis and to see how the condition progresses and responds to treatment. For example, whether a particular biomarker is decreasing or increasing may help a physician know whether sepsis is improving or worsening. The physician may then increase or decrease IV fluids or may change antibiotics.