Table of ContentsView AllTable of ContentsWhat Is a Procalcitonin Test?When It Is UsedWho Is at Risk of Sepsis?What Do the Test Results Mean?Other Possible Causes

Table of ContentsView All

View All

Table of Contents

What Is a Procalcitonin Test?

When It Is Used

Who Is at Risk of Sepsis?

What Do the Test Results Mean?

Other Possible Causes

This article explains how the procalcitonin test works, how the results are interpreted, and what the test can and cannot tell you.

Verywell / Laura Porter

When a bacterial infection becomes systemic, meaning that it spreads throughout the body, procalcitonin levels can shoot up dramatically. The higher the level, the greater the likelihood of sepsis.

Other conditions can also increase procalcitonin but usually only to mild to moderate levels. Having elevated procalcitonin does not necessarily mean you have sepsis. It is simply an indication of a systemic infection that needs further investigation.

Other tests will be used to confirm the diagnosis. These may include blood cultures, acomplete blood count (CBC), urinalysis,liveror kidney function tests, and imaging tests likeultrasound, computed tomography (CT), or magnetic resonance imaging (MRI).

Difference Between Sepsis and Septicemia

When Is a Procalcitonin Test Used?

The procalcitonin test is ordered when there is a suspicion of sepsis. It is frequently used in emergency rooms or intensive care units when people show signs of sepsis, including high fever, difficulty breathing, low blood pressure, and confusion.

The test is important because sepsis can be difficult to diagnose and doesn’t always cause symptoms in the early stages. It is possible, for example, for procalcitonin levels to be low in the very early stages and increase steeply over hours or days.

On the other hand, it is possible to have high procalcitonin levels and no clear symptoms in the early stages. It is only when the extreme inflammation begins to affect organs that severe symptoms will appear.

By testing procalcitonin levels early, doctors can prescribe treatment before the condition becomes serious or life-threatening.

Warning Signs of SepsisSepsis occurs when your body has an extreme reaction to an infection that results in life-threatening inflammation. Symptoms include confusion or disorientation, shortness of breath, rapid heart beat, fever, feeling cold, pain, or clammy skin.

Warning Signs of Sepsis

Sepsis occurs when your body has an extreme reaction to an infection that results in life-threatening inflammation. Symptoms include confusion or disorientation, shortness of breath, rapid heart beat, fever, feeling cold, pain, or clammy skin.

How Bacteremia Leads to Sepsis or Septic Shock

More than 1.7 million adults in the U.S. develop sepsis every year, according to the Centers for Disease Control and Prevention (CDC). While anyone who gets an infection can develop sepsis, certain groups have a higher chance of getting it because they are more susceptible to infections. They include:

The procalcitonin test cannot diagnose infections. It can show your doctor if sepsis may be occurring, how severe it may be, and whether it is likely to progress to septic shock, which occurs when blood pressure drops dangerously low.

If the symptoms are severe but the procalcitonin level is low, the cause is more likely viral. Higher procalcitonin levels indicate that the infection is probably bacterial. Knowing what type of infection you have can help ensure that the appropriate treatment is given and that if you have a virus, you aren’t needlessly prescribed antibiotics.

A moderate to mildly high level of procalcitonin may also be due to something aside from an infection, such as tissue injury or a chronic condition that causes an elevation in procalcitonin.

Studies have shown that high procalcitonin levels in people with sepsis are associated with a greater risk of septic shock and death.

What Causes High Procalcitonin?

While elevated procalcitonin levels can be a strong indication of sepsis, even minor infections like a tooth abscess can cause procalcitonin levels to rise. Even so, high levels usually point to sepsis.

When procalcitonin levels are low to moderate, sepsis may be a possible cause. But other causes may be to blame. These include conditions that cause severe tissue injury, such as:

People who have certain conditions, such as COPD or chronic kidney disease, may also have elevated baseline levels of procalcitonin.

Risk of Sepsis in Older Adults

Summary

A procalcitonin test is a type of blood test that can help diagnose sepsis and determine a person’s risk of severe illness, shock, and death. Because sepsis worsens rapidly, an early diagnosis can ensure that the right medications are prescribed before the condition turns severe.

Based on how high or low the procalcitonin levels are, doctors can also get a better idea as to whether the cause is an infection or another condition. The test can also help differentiate between a bacterial and viral infection or a systemic or local infection.

A Word From Verywell

A procalcitonin level on its own only predicts a likelihood that an infection is present. The procalcitonin result is a guide, not a diagnosis.

People do not receive treatment based on a procalcitonin level alone. A battery of tests is needed, and the treatment is based on an interpretation of the results and the clinical judgment of the physician.

The true value of the procalcitonin level is that it can lead to the early treatment of sepsis. Treating the infection even a few hours earlier can make the difference between an illness that responds to antibiotics and one that lands you in intensive care.

8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.AlRawahi, A. N., AlHinai, F. A., Doig, C. J., Ball, C. G., Dixon, E., Xiao, Z., & Kirkpatrick, A. W. (2019).The prognostic value of serum procalcitonin measurements in critically injured patients: A systematic review.Critical Care,23(1). https://doi.org/10.1186/s13054-019-2669-1MedlinePlus.Procalcitonin test.Samsudin I, Vasikaran SD.Clinical utility and measurement of procalcitonin.Clin Biochem Rev. 2017;38(2):59-68.National Institute of General Medical Sciences.Sepsis.Centers for Disease Control and Prevention.CDC urges early recognition, prompt treatment of sepsis.Centers for Disease Control and Prevention.About sepsis.UpToDate.Procalcitonin use in lower respiratory tract infections.Pandey S, Garg R, Kant S, Verma A, Gaur P.Serum procalcitonin levels in chronic obstructive pulmonary disease patients in North Indian Population.Ann Afr Med. 2019;18(2):103-107. doi:10.4103/aam.aam_44_18

8 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.AlRawahi, A. N., AlHinai, F. A., Doig, C. J., Ball, C. G., Dixon, E., Xiao, Z., & Kirkpatrick, A. W. (2019).The prognostic value of serum procalcitonin measurements in critically injured patients: A systematic review.Critical Care,23(1). https://doi.org/10.1186/s13054-019-2669-1MedlinePlus.Procalcitonin test.Samsudin I, Vasikaran SD.Clinical utility and measurement of procalcitonin.Clin Biochem Rev. 2017;38(2):59-68.National Institute of General Medical Sciences.Sepsis.Centers for Disease Control and Prevention.CDC urges early recognition, prompt treatment of sepsis.Centers for Disease Control and Prevention.About sepsis.UpToDate.Procalcitonin use in lower respiratory tract infections.Pandey S, Garg R, Kant S, Verma A, Gaur P.Serum procalcitonin levels in chronic obstructive pulmonary disease patients in North Indian Population.Ann Afr Med. 2019;18(2):103-107. doi:10.4103/aam.aam_44_18

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

AlRawahi, A. N., AlHinai, F. A., Doig, C. J., Ball, C. G., Dixon, E., Xiao, Z., & Kirkpatrick, A. W. (2019).The prognostic value of serum procalcitonin measurements in critically injured patients: A systematic review.Critical Care,23(1). https://doi.org/10.1186/s13054-019-2669-1MedlinePlus.Procalcitonin test.Samsudin I, Vasikaran SD.Clinical utility and measurement of procalcitonin.Clin Biochem Rev. 2017;38(2):59-68.National Institute of General Medical Sciences.Sepsis.Centers for Disease Control and Prevention.CDC urges early recognition, prompt treatment of sepsis.Centers for Disease Control and Prevention.About sepsis.UpToDate.Procalcitonin use in lower respiratory tract infections.Pandey S, Garg R, Kant S, Verma A, Gaur P.Serum procalcitonin levels in chronic obstructive pulmonary disease patients in North Indian Population.Ann Afr Med. 2019;18(2):103-107. doi:10.4103/aam.aam_44_18

AlRawahi, A. N., AlHinai, F. A., Doig, C. J., Ball, C. G., Dixon, E., Xiao, Z., & Kirkpatrick, A. W. (2019).The prognostic value of serum procalcitonin measurements in critically injured patients: A systematic review.Critical Care,23(1). https://doi.org/10.1186/s13054-019-2669-1

MedlinePlus.Procalcitonin test.

Samsudin I, Vasikaran SD.Clinical utility and measurement of procalcitonin.Clin Biochem Rev. 2017;38(2):59-68.

National Institute of General Medical Sciences.Sepsis.

Centers for Disease Control and Prevention.CDC urges early recognition, prompt treatment of sepsis.

Centers for Disease Control and Prevention.About sepsis.

UpToDate.Procalcitonin use in lower respiratory tract infections.

Pandey S, Garg R, Kant S, Verma A, Gaur P.Serum procalcitonin levels in chronic obstructive pulmonary disease patients in North Indian Population.Ann Afr Med. 2019;18(2):103-107. doi:10.4103/aam.aam_44_18

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