Procalcitonin — The Bacteria Detector
Fever. Inflammation. Is it bacteria? A virus? Something else entirely? These are questions that matter — especially when antibiotics are on the table. Procalcitonin (PCT) helps answer them. Unlike CRP, which spikes in response to all kinds of inflammation, PCT is picky. It rises mainly during bacterial infections, making it incredibly useful for guiding antibiotic decisions and assessing how serious an infection really is.
Why Test Procalcitonin Blood Test?
PCT helps distinguish between bacterial and viral infections, guides decisions about starting or stopping antibiotics, assesses the severity of conditions like sepsis, and monitors treatment response. It's especially valuable when clinical signs alone aren't enough to determine whether antibiotics are needed.
What Do High Procalcitonin Blood Test Levels Mean?
Elevated PCT strongly suggests a bacterial infection, with higher numbers correlating to more severe infections. Very high levels may indicate sepsis or other life-threatening bacterial conditions requiring urgent treatment. PCT can also be mildly elevated after major surgery or trauma.
What Do Low Procalcitonin Blood Test Levels Mean?
Low or normal PCT suggests bacteria aren't the problem. If you have inflammatory symptoms with low PCT, a viral infection or non-infectious cause is more likely. Low PCT can also support the decision to safely skip or stop antibiotics — which is a win for everyone.
Symptoms to Watch For
- Fever with suspected bacterial cause
- Signs of sepsis (confusion, rapid breathing, low blood pressure)
- Cough and respiratory symptoms pointing to pneumonia
- Post-surgical infection concerns
- Persistent fever that won't respond to standard treatment
Who Should Get Tested?
- Anyone with fever of unknown origin
- Those being evaluated for sepsis or serious bacterial infection
- People with respiratory symptoms where pneumonia is suspected
- Hospital patients where antibiotic guidance is needed
- Anyone with persistent infection symptoms
How to Prepare for Your Test
No special prep needed. Just bring valid ID on test day.
Frequently Asked Questions
How is procalcitonin different from CRP?
Can PCT be used to monitor antibiotic treatment?
Reviewed by
Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
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The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.