Serum Iron tests measure different substances in the blood to check iron levels in your body. Iron is a mineral that’s essential for making red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body. Iron is also important for healthy muscles, bone marrow, and organ function. Iron levels that are too low or too high can cause serious health problems.
Different types of iron tests include:
- Serum iron test, which measures the amount of iron in the blood
- Transferrin test, which measures transferrin, a protein that moves iron throughout the body
- Total iron-binding capacity (TIBC), which measures how well iron attaches to transferrin and other proteins in the blood FFP
- Ferritin blood test, which measures how much iron is stored in the body
Fe+2; Ferric ion; Fe++; Ferrous ion; Iron – serum; Anemia – serum iron; Hemochromatosis – serum iron
What does a serum iron test check for?
Serum iron is not a routine test. It’s usually ordered as a follow-up when a more common test reveals abnormal results. Such tests include complete blood count or hemoglobin test.
Your doctor may also order a serum iron test if you’re showing symptoms of anemia. Abnormal iron tests could be a sign of iron deficiency or iron overload.
Symptoms of abnormal iron levels
Early symptoms of iron deficiency (anemia) include:
- chronic fatigue
- muscle weakness
You may develop other symptoms as your condition worsens. These may include:
- difficulty concentrating
- tongue and mouth sores
- pica (the compulsion to eat nonfood items, such as paper or ice chips)
- misshapen nails
Symptoms of iron overload (when your body produces too much iron) include:
- pain in your abdomen and joints
- bronzing or darkening of skin
- heart problems
- lack of energy
- lack of sex drive
- weight loss
- muscle weakness
How to Prepare for the Test
Iron level can change, depending on how recently you ingested iron. Your health care provider will likely have you do this test in the morning or after fasting.
Certain medicines may affect the results of this test. Your provider will tell you if you need to stop taking any medicines. DO NOT stop any medicine before talking to your provider.
Medicines that can affect the test result include:
- Birth control pills and estrogens
- Blood pressure drugs
- Cholesterol drugs
- Deferoxamine (removes excess iron from the body)
- Gout drugs
Why do I need these tests?
You may need these tests if your healthcare provider thinks your iron level is too low or too high. Not having enough iron in your diet is the most common cause of anemia. It’s the most common type of diet deficiency in the U.S. You may need this test to look at your diet, nutrition, liver, or other conditions that cause iron to be low, such as blood loss or pregnancy.
Symptoms of iron deficiency include:
- Being tired and feeling weak
- Getting frequent infections
- Feeling cold all the time
- Having swelling in the tongue
- Struggling to keep up at school or work
- In children, having delayed mental development
Symptoms of too much iron can include:
- Feeling tired and weak
- Joint pain
- Belly pain
What other tests might I have along with this test?
Iron, TIBC, and transferrin blood tests are almost always done together. Your blood may also be checked for:
- Level of your hemoglobin
- Your percentage of red blood cells, called hematocrit
- The number of all the cells in your blood, called a complete blood count (CBC)
Why the Test is Performed
Your provider may recommend this test if you have:
- Signs of low iron (iron deficiency)
- Signs of too much iron
- Anemia caused by a chronic disease
What to expect during the test
The serum iron test is a relatively simple test with minimal risk. In preparation, it may be necessary to fast for up to 12 hours before the test and to avoid taking certain other medications during this time.
A doctor, nurse, or phlebotomist will draw a small sample of blood from the person’s arm and send it to a lab for testing. They will then explain the person’s results to them in a follow-up appointment before determining the appropriate next steps.
Interpreting the results
The test will measure the total iron level in the serum in micrograms of iron per deciliter of blood (mcg/dL).
In addition to the serum iron test, many people will have a serum transferrin level test. Transferrin is a type of protein that is responsible for transporting iron in the blood.
Transferrin levels can also help a doctor to determine if there is too much or too little iron in the blood. The unit of measurement for transferrin is milligrams per deciliter (mg/dL).
Another common test measures the total iron binding capacity, called TIBC for short, also in mcg/dL. This shows the amount of iron that transferrin can bind to in the blood.
The results can vary over time depending on a person’s overall health. Defined normal levels tend to vary from one lab to another but typically fall within the following ranges:
- TIBC: 262–474 mcg/dL
- Total serum iron: 26–170 mcg/dL in women and 76–198 mcg/dL in men
- Transferrin saturation: 204–360 mg/dL
Normal value range is:
- Iron: 60 to 170 micrograms per deciliter (mcg/dL), or 10.74 to 30.43 micromoles per liter (micromol/L)
- Total iron binding capacity (TIBC): 240 to 450 mcg/dL, or 42.96 to 80.55 micromol/L
- Transferrin saturation: 20% to 50%
The numbers above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.
What Abnormal Results Mean
Higher-than-normal iron level may be a sign of:
- Too much iron in the body (hemochromatosis)
- Anemia due to red blood cells being destroyed too quickly (hemolytic anemia)
- Liver tissue death
- Inflammation of the liver (hepatitis)
- Iron poisoning
- Frequent blood transfusions
Lower-than-normal level may be a sign of:
- Long-term digestive tract bleeding
- Heavy menstrual bleeding
- Intestinal conditions that cause poor absorption of iron
- Not enough iron in the diet
What do my test results mean?
Test results may vary depending on your age, sex, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
Normal results of iron testing may be different for men, women, and children. Iron and TIBC are measured in micrograms per deciliter (mcg/dL). Normal results for iron are:
- 65 to 175 mcg/dL for men
- 50 to 170 mcg/dL for women
- 50 to 120 mcg/dL for children
Normal results for TIBC are 250 to 450 mcg/dL for men and women.
Some common causes for a low amount of iron in your blood include:
- Iron deficiency anemia
- Other types of anemia
- Blood loss over time
- Long-standing infections or diseases
- Last 3 months of pregnancy
Some common causes for too much iron in your blood include:
- Conditions that cause red blood cells to die, called hemolytic anemia
- Iron or lead poisoning
- Iron overload, such as from hemochromatosis
- Many blood transfusions
- Liver damage
Your healthcare provider will look at your iron level along with the TIBC, transferrin, and possibly other tests to see what the results mean.
How to correct iron levels
Following serum iron and other iron-related tests, a doctor will suggest ways in which a person can correct their iron levels.
People with low levels of iron may need to make changes to their diet or take iron supplements.
They may need to eat more iron-rich foods, which include:
- beef liver
- red meat
- dark green, leafy vegetables
- whole grains
Conversely, those with an elevated iron level should avoid iron in their diet. They may also need to avoid vitamin C supplements, although this is unnecessary in most cases.
If a person has a high iron level as a result of chronic liver disease, they should avoid anything that could hurt the liver more, such as consuming alcohol.
A person with too much iron may also need to undergo a process called phlebotomy, which removes blood from the body. Read more
Is there anything else I need to know about iron tests?
Your health care provider may order other blood tests to help check your iron levels. These include:
- Hemoglobin test
- Hematocrit test
- Complete blood count
- Mean corpuscular volume