Serum Ferritin

Ferritin is a protein that stores iron, a nutrient that is necessary for the production of healthy red blood cells and the distribution of oxygen throughout the body.

When the body uses iron, a small amount of ferritin is released from cells and circulates in the blood. Your ferritin level reflects the total amount of iron stored in your body.

Having too little or too much iron in the body can be a sign of a serious health condition. Doctors will order a ferritin test with other iron tests if you have signs of anemia, iron overload, or after a complete blood count (CBC) test indicates low hemoglobin or hematocrit levels.

Purpose of the test

The purpose of a ferritin test is to determine whether your body is storing a normal amount of iron.

The result of a ferritin test may be interpreted alone, but most often it is evaluated at the same time as blood tests, liver function tests, or iron studies. Ferritin testing is used to screen for, diagnose, or monitor certain conditions.

Screening

Ferritin testing is used as a screening tool along with other blood tests to look for low levels of iron or iron deficiency, before symptoms develop. Screening with a ferritin test is typically only used in patients who are at an especially high risk for iron deficiency, including:

• Female adolescents who are underweight, experience heavy blood loss during menstruation, or who do not get enough iron in their diet
• People who are pregnant

Diagnosis

Diagnostic testing aims to find the cause of a patient’s symptoms. A ferritin test can help to diagnose or rule out the following conditions: 

• Iron deficiency anemia: If your body’s iron levels are consistently low, iron deficiency can progress to anemia. Low iron levels in the blood reduce production of red blood cells, which affects the body’s ability to deliver enough oxygen to muscles and organs.

• Iron overload: High levels of iron are referred to as iron overload or hemochromatosis. Your body does not have a natural way to get rid of extra iron and it will deposit it in body tissues, like the liver, heart, and pancreas. Iron overload can cause serious damage to your organs.

• Liver disease: A large amount of our iron is stored in ferritin proteins in the liver. When the liver is damaged or diseased, iron and ferritin can leak from the liver into the blood. Ferritin testing can help diagnose liver conditions such as alcohol abuse, cirrhosis, and Hepatitis B and C infection.
• Restless legs syndrome (RLS): RLS is characterized by uncomfortable feelings in the limbs and a strong urge to move them, especially when sitting or laying. Ferritin testing can determine whether iron deficiency may be contributing to RLS symptoms.
• Adult-onset still disease (AOSD): AOSD is a rare condition that causes joint pain and swelling, fevers, rash, and high levels of ferritin.