Serum/plasma mass concentration of procalcitonin (PCT)

What Is Procalcitonin Used For?

Procalcitonin is primarily used to identify bacterial infections, which may require different treatment than viral infections. Higher levels often suggest a bacterial infection, while lower levels may indicate a viral illness or less severe condition.

How Is the Test Performed?

A blood sample is drawn from a vein, usually in your arm. The blood is then processed to separate serum or plasma, where the procalcitonin protein is measured using a sensitive laboratory technique.

Why Might Your Doctor Order This Test?

Your doctor may order this test if you have symptoms of infection (such as fever, chills, or cough), suspected sepsis, or if you’re receiving treatment for an infection. It can also help monitor response to antibiotics or assess risk in high-risk patients (e.g., hospitalized patients).

What Are Common Causes of Elevated PCT?

Elevated procalcitonin levels are most commonly seen in bacterial infections (e.g., pneumonia, sepsis, urinary tract infections) or severe inflammatory conditions. Rarely, it may be elevated in viral infections or non-infectious conditions like pancreatitis or certain cancers.