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Iron (Serum or Plasma Concentration)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of iron present in your blood, either in serum or plasma. Iron is an essential mineral that helps carry oxygen in your red blood cells.

Quick summary

["Iron levels help assess your body’s ability to produce healthy red blood cells and prevent anemia."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
50198-1
Short code
Iron sp1 SerPl-mCnc
Synonyms
Iron sp1 SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
60
Ref high
170
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83540
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 Is Done

Your healthcare provider may order this test if you have symptoms of iron deficiency, such as fatigue, pale skin, or unusual tiredness. It may also be used to diagnose or monitor conditions like anemia, certain blood disorders, or to check for excessive iron storage (hemochromatosis).

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 a blood draw, but this depends on the lab’s protocol. Bring any medications you’re taking to your appointment.

During the Test

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the procedure is quick and usually painless. You can resume normal activities immediately afterward.

Possible Results and Next Steps

Results are compared to standard reference ranges, though exact values may vary by lab. Low iron levels may lead to further testing for anemia or dietary adjustments. High levels could signal conditions like hemochromatosis or excessive iron supplements.

Reference range

NCBI: Serum Iron Male 65-180; Female 50-170 µg/dLN/A

Specimen: serum

Fasting for 12 hours preferred. Iron supplements should be stopped 24 hours before if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Iron Level

Frequently asked questions

What causes low iron levels?
Low iron levels can result from dietary deficiencies, chronic blood loss (e.g., heavy periods, gastrointestinal bleeding), poor absorption (e.g., celiac disease), or increased demand (e.g., pregnancy). Some medications or medical conditions may also contribute.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Follow-up may be scheduled if your results are outside the expected range.
Can I eat or drink before the test?
Most labs recommend fasting for 8–12 hours before a blood draw for iron testing, but always confirm with your provider or lab technician. Avoid caffeine or alcohol before testing if instructed.
  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 17, 2026. · Read our editorial policy