Glossary term
HPF (High Power Field)
Also known as: HPF, high power field, per high power field, /hpf
Part of: How to read a report
- Reading time
- 3 min read
- Last reviewed
- Last reviewed January 1970
- Reading level
- Written in plain English
- Reviewed by
- Reviewed by Medipher Editorial Team
The area visible down a microscope at high magnification, used as the unit when cells are counted by eye.
Medipher explains medical wording in plain English — it does not diagnose or replace a clinician. If this is a medical emergency, call your local emergency number immediately.
What is this?
When a laboratory scientist examines a sample under a microscope, they count what they can see in one field of view at high magnification. Results are then reported as a number per high power field, abbreviated HPF.
This is a practical, approximate way of describing how much of something is present — red cells, white cells, crystals, bacteria — rather than a precise machine measurement.
Because the count depends on the sample and on the field examined, small differences between reports are expected.
Why is it important?
It explains notation such as '5–10 red cells per HPF', which is a microscopy observation rather than a machine measurement.
Where you'll see it: Urine microscopy and other reports where a scientist counts what is seen under a microscope.
Does an abnormal result always mean something is wrong?
Not necessarily. A number that sits outside the printed range is a prompt for interpretation — not a diagnosis.
- A single result rarely gives the full picture — clinicians interpret it alongside your symptoms.
- Your medical history, medications and other blood tests all shape the meaning of one value.
- Small movements just outside the reference range are common and often not concerning.
- Repeat testing over time is frequently more useful than any single number.
What might happen next?
- Read HPF findings alongside the rest of the report and your symptoms.
- Ask the requesting service what the finding means in your situation.
One result rarely tells the whole story. Clinicians look at your symptoms, medical history, medications and other tests together — and a single value that sits slightly outside the reference range is often normal for you. Repeat testing over time is frequently more useful than any one number. Medipher helps you understand what a result means in plain English, but it cannot diagnose medical conditions or replace advice from a doctor, nurse or pharmacist.
When should I speak to a healthcare professional?
Speak with your GP or another healthcare professional if:
- You've been asked to repeat the test.
- You're experiencing new or worsening symptoms.
- Your clinician has flagged the result as needing follow-up.
- You don't understand your results or feel unsure what to do next.
If you have severe symptoms — chest pain, severe breathlessness, fainting, heavy bleeding or feel very unwell — seek urgent help. If this is a medical emergency, call your local emergency number immediately. Medipher is designed to help explain medical information and is not an emergency service.
Frequently asked questions
Related blood tests
Terms clinicians often look at alongside HPF (High Power Field).
- Laboratory commentA short free-text note added by the laboratory to explain, qualify or advise on a result.
- Reference rangeThe band of values a laboratory expects to see in most healthy people tested in the same way.
- Not isolatedUsed in microbiology to say that a particular organism did not grow in the culture from your sample.
Related guides
Still unsure what your result means?
This page explains one medical term. If you have a blood test, GP letter or hospital report, Medipher can explain your entire document in plain English.
- what your results mean
- unfamiliar medical terminology
- what your clinician may be monitoring
- useful questions to ask at your next appointment
Sources
General patient information referenced when writing this page.
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About this page
- Author
- Omer Suliman
- Medical reviewer
- Clinical review pending
- Last reviewed
- January 1970
- Last updated
- January 1970
Evidence. Written from public patient-information sources including the NHS, NICE and the Association for Laboratory Medicine, and reviewed for plain-English accuracy before publication.
Educational content only. Medipher explains medical language in plain English. It does not diagnose, and it is not a substitute for advice from a doctor, nurse or pharmacist. Read the medical disclaimer.
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A short summary and recommended next reads are just below.
Continue learning
- Next upLaboratory commentA short free-text note added by the laboratory to explain, qualify or advise on a result.
- Next upReference rangeThe band of values a laboratory expects to see in most healthy people tested in the same way.
- Next upNot isolatedUsed in microbiology to say that a particular organism did not grow in the culture from your sample.
This glossary entry is general health information, not medical advice. Medipher explains medical wording in plain English and does not diagnose, provide treatment advice, or replace a GP, doctor, nurse or pharmacist. Always discuss your results with a qualified clinician.