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Iron, Serum or Plasma (Mass Concentration)

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

This test measures the amount of iron present in your blood serum or plasma, which helps assess iron stores and identify potential deficiencies or excesses.

Quick summary

["Iron levels help diagnose anemia or iron overload conditions."]

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

Key facts at a glance

LOINC
74744-4
Short code
Deprecated S lugdunensis sodA Bld Pos Ql Prb Mag
Synonyms
Deprecated S lugdunensis sodA Bld Pos Ql Prb Mag
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-mag-capture
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test to check for iron deficiency (which can cause fatigue, weakness, or pale skin) or iron overload (which may lead to organ damage). It’s often done if you have symptoms like extreme tiredness, unusual appetite, or unexplained weight changes. It may also be part of routine blood work or screening for conditions like hemochromatosis.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it’s done on an empty stomach. Bring any medications you’re taking to your appointment. If you’re taking iron supplements, let your provider know—this may affect results.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are compared to a general reference range, which can vary slightly by lab. Low iron levels may indicate anemia or poor absorption of iron, while very high levels could signal conditions like hemochromatosis or excessive intake. Your provider will interpret results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low iron levels (iron deficiency) are common and can cause fatigue, pale skin, weakness, or difficulty concentrating. It’s often linked to poor diet, chronic blood loss (e.g., from heavy periods or digestive issues), or increased demand (e.g., during pregnancy). High iron levels may signal iron overload, which can damage organs over time and is more common in people with genetic conditions like hemochromatosis. Regular monitoring is important for those with known risk factors.

Short name

Iron Level

Frequently asked questions

How often should I get this test?
Your provider will determine how often you need this test based on your health status. For example, pregnant women, people with chronic illnesses, or those with a history of iron-related conditions may need it more frequently. Follow-up tests are often scheduled if your results are outside the normal range.
What can affect my iron test results?
Several factors can influence iron test results, including recent blood loss (e.g., from surgery or heavy periods), certain medications (like blood thinners or iron supplements), or conditions that affect iron absorption (e.g., celiac disease). If you’re unsure about your medications or recent health changes, discuss them with your provider.
What if my iron level is too low?
If your iron level is low, your provider may recommend dietary changes (e.g., eating more iron-rich foods like lean meats, spinach, or fortified cereals), supplements (iron tablets or injections), or treatments for underlying causes like bleeding or malabsorption. Lifestyle adjustments, such as avoiding excess coffee or tea with meals (which can interfere with iron absorption), may also help.
  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