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Serum Angiotensin-Converting Enzyme (S-ACE) Activity

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

This test measures the activity level of angiotensin-converting enzyme (ACE) in your blood serum. ACE plays a role in regulating blood pressure and fluid balance.

Quick summary

["ACE activity helps assess conditions affecting lung and kidney function."]

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

Key facts at a glance

LOINC
32946-6
Short code
SNA Angle Skull CT
Synonyms
SNA Angle Skull CT
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ct-measured
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

What Is Angiotensin-Converting Enzyme (ACE)?

Angiotensin-converting enzyme (ACE) is an enzyme that helps control blood pressure and fluid balance in your body. It converts a protein called angiotensin I into angiotensin II, a hormone that narrows blood vessels and raises blood pressure. ACE also breaks down a substance called bradykinin, which helps regulate blood flow and inflammation. Your body produces ACE in several tissues, including the lungs, kidneys, and blood vessels.

Why Might You Need This Test?

Your healthcare provider may order this test to evaluate conditions linked to ACE, such as certain lung diseases (e.g., sarcoidosis, lymphangioleiomyomatosis), kidney disorders, or reactions to medications that affect ACE levels.

How Is This Test Performed?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab, where ACE activity is measured using an enzymatic method to detect its function in converting substrates.

What Are Common Uses?

This test is often used to diagnose or monitor conditions like chronic obstructive pulmonary disease (COPD), certain infections, or to check for side effects of ACE inhibitors (medications used to treat high blood pressure or heart failure).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated ACE levels may suggest conditions like sarcoidosis (a disease causing inflammation in organs) or certain infections (e.g., tuberculosis). Lower than expected levels could indicate kidney disease or exposure to ACE inhibitors. Always discuss results with your provider, as they’ll consider your full medical history and symptoms.

Short name

S-ACE

Frequently asked questions

What does an abnormal ACE level mean?
An abnormal ACE level doesn’t have a single interpretation—it depends on your symptoms, medical history, and other test results. For example, high ACE might point to lung diseases or infections, while low ACE could relate to kidney issues or medication use. Your provider will review these details with you.
How often should I get this test?
The frequency depends on your health condition and treatment plan. Your provider will determine how often to check ACE levels based on your diagnosis, symptoms, or response to treatment.
Can lifestyle changes affect ACE levels?
ACE levels can be influenced by certain medications (like ACE inhibitors) or conditions affecting kidney or lung function. Lifestyle factors such as smoking or chronic infections may also play a role, but results should always be interpreted by a healthcare provider.
  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