Which of the following markers is indicative of inflammation?

The reason the increased erythrocyte sedimentation rate (ESR) is indicative of inflammation is that ESR measures how quickly red blood cells settle in a tube of blood. During times of inflammation, various proteins are released into the bloodstream, such as fibrinogen and other acute-phase reactants. These proteins can increase the viscosity of the blood and alter the normal settling behavior of red blood cells, causing them to settle more quickly. Therefore, a higher ESR reading is commonly used as a marker of ongoing inflammatory processes in the body.

In contrast, increased hemoglobin levels would not typically indicate inflammation; rather, they might suggest a compensatory mechanism to improve oxygen delivery in cases of chronic hypoxia or might indicate dehydration. A decreased level of C-reactive protein (CRP) would suggest a resolution of inflammation, as CRP is an acute-phase reactant that rises in response to inflammation. Increased platelet counts can occur in various conditions, including inflammation, but are not as specific as ESR for measuring the overall inflammatory response. Thus, the increase in ESR stands out as a clear indicator of inflammation.