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Atrial Natriuretic Peptide (ANP) – Serum

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of atrial natriuretic peptide, a hormone produced by your heart’s atria (upper chambers) in response to high blood pressure or volume overload.

Quick summary

["ANP helps your body reduce fluid retention and blood pressure by signaling your kidneys to excrete sodium and water."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
55442-8
Short code
Deprecated AT III PPP
Synonyms
Deprecated AT III PPP
Category
chemistry
Sample
plasma
Container
Lavender-top (EDTA) or Green-top (Heparin)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your doctor may order this test to evaluate heart function, especially if you have symptoms like shortness of breath, swelling, or rapid heartbeat. It can also help assess conditions such as heart failure, fluid overload, or certain types of hypertension.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves drawing blood from your vein. Stay hydrated unless instructed otherwise.

How the Test Works

A blood sample is taken from a vein in your arm. The sample is sent to a lab, where it is analyzed to measure the amount of atrial natriuretic peptide in your serum.

What the Results Mean

Higher than normal levels may indicate conditions like heart failure, pulmonary edema, or severe volume overload. Lower levels might suggest conditions such as atrial fibrillation or certain heart diseases. Your doctor will interpret the results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated ANP levels are strongly associated with heart-related issues, including fluid overload in heart failure or conditions causing high blood pressure. It can help guide treatment decisions, such as adjusting medications or monitoring heart function over time.

Short name

ANP Level

Frequently asked questions

What causes ANP levels to be high?
High ANP levels are often linked to conditions that increase pressure or volume in your heart, such as heart failure, pulmonary hypertension, or severe fluid retention. Other rare causes may include certain tumors or kidney problems.
What happens if my ANP level is abnormal?
If your ANP level is elevated, your doctor may recommend further testing or adjustments to your treatment plan, such as medications to manage heart function or fluid balance. If low, it may prompt additional evaluation for underlying heart conditions.
Can diet or medications affect ANP levels?
Yes, certain medications (like diuretics or blood pressure drugs) can influence ANP levels. Avoiding certain foods or supplements that may affect heart function, such as excessive salt or caffeine, can also help ensure accurate results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy