PCT<0.05
Healthy individuals

PCT<0.5
Systemic infection (sepsis) is not likely
Local bacterial infection is possible

0.5<PCT<2
Systemic infection (sepsis) is possible but various conditions are known to induce PCT as well

2<PCT<10
Systemic infection (sepsis) is likely, unless other causes are known.

10<PCT
Important systemic inflammatory response, almost exclusively due to severe bacterial sepsis or septic shock.