What Diagnostic Tests are Recommended for Iron Deficiency?

Welcome to our guide on the ins and outs of diagnosing iron deficiency anemia. As this condition leads so many people to find our best-selling nano iron product, we wanted to explain how the tests work, and what a low iron count looks like.

Iron deficiency anemia involves a low red blood cell count or not enough hemoglobin, leading to a range of symptoms that can affect your quality of life.

So, how do healthcare professionals figure out if you have iron deficiency anemia?

Well, that's where diagnostic tests come in, and there's more to it than a simple blood test.

In this guide, we'll walk you through the different types of tests you might encounter, from the standard blood tests to the more advanced diagnostic procedures for severe cases.

We'll also delve into the consultation phase, as speaking with a specialist can give you a more complete picture of what's going on. Finally, we'll touch on what long-term care looks like, to help you understand how ongoing monitoring plays a part in managing the condition effectively.

Iron fatigue

How is Iron-Deficiency Anemia Diagnosed?

The journey to a conclusive diagnosis usually starts with blood tests, which provide an essential overview of your hemoglobin levels, iron concentration, and other relevant factors. Here's what you can expect:

Core Blood Tests for Iron Deficiency Anemia

These are the go-to tests that healthcare professionals often rely on for initial screening and diagnosis. They give a broad overview and can signal if further tests are necessary.

Test Name Purpose Indicators of Iron Deficiency Anemia Normal Ranges
Complete Blood Count (CBC) To evaluate the overall health and to detect a variety of disorders, including anemia Low red blood cell count, low hemoglobin RBC: 4.5 to 5.5 million cells/mcL; Hemoglobin: Men, 13.8 to 17.2 grams per deciliter (g/dL); Women, 12.1 to 15.1 g/dL
Serum Iron Levels To measure the amount of circulating iron in the blood Low serum iron levels 50-170 micrograms per deciliter (mcg/dL)
Total Iron-binding Capacity (TIBC) To measure the blood's ability to bind and transport iron High TIBC levels 240-450 mcg/dL
Ferritin Test To gauge the body's iron storage levels Low ferritin levels Men: 24-336 nanograms per milliliter (ng/mL); Women: 11-307 ng/mL
Transferrin Saturation To calculate the percentage of transferrin that is saturated with iron Low percentage of transferrin saturation 20-50%

Complete Blood Count (CBC) - Primary Blood Test for Anemia Screening

At the beginning of your diagnostic process, a Complete Blood Count (CBC) is typically the first test ordered. It provides a general overview of your blood health and is essential for identifying any form of anemia. If the CBC suggests iron deficiency, tests like Serum Iron Levels, Total Iron-Binding Capacity (TIBC), and Ferritin will usually follow to confirm the diagnosis and assess the severity.

Serum Iron Levels - Core Blood Test for Iron Deficiency

The Serum Iron Levels test is a key diagnostic tool that gauges the quantity of iron present in your bloodstream. This test is crucial because it helps to confirm or rule out the possibility of iron deficiency, one of the leading causes of anemia.

The essence of the test lies in its capacity to measure circulating iron. If the test reveals lower than normal levels, it typically suggests that your body doesn't have enough iron to perform essential functions like oxygen transport via red blood cells.

However, there are some nuances to understand. Serum iron levels can vary throughout the day due to natural circadian rhythms, and they can also be influenced by recent food intake. Therefore, the test is often conducted under fasting conditions, or healthcare professionals may recommend the timing for the test to control for these variables.

Total Iron-binding Capacity (TIBC) Test

The Total Iron-Binding Capacity (TIBC) test serves as a valuable companion to the Serum Iron Levels test in the diagnostic process for iron deficiency. Essentially, this test quantifies your blood's ability to bind and transport iron throughout your body, a crucial function for overall health and wellbeing.

Unlike serum iron levels, which indicate the amount of circulating iron, TIBC provides insight into your body's capacity to manage and utilise that iron. In instances where your body is low on iron, TIBC levels tend to be elevated. This is your body's compensatory mechanism to maximise iron capture and utilisation from available sources.

It's often the case that the TIBC test is ordered in conjunction with the Serum Iron Levels test. This pairing provides a more comprehensive view of your iron status. It allows for a nuanced understanding of not just how much iron is present, but also how well your body is able to manage that iron.

Ferritin Test - Most Reliable Blood Test for Iron Deficiency

The Ferritin Test holds a unique status as arguably the most reliable blood test for diagnosing iron deficiency. This test measures the levels of ferritin, a protein that plays a pivotal role in storing iron within your cells. Ferritin serves as an internal reserve, releasing iron when your body needs it, thereby keeping the body's iron metabolism in balance.

When ferritin levels are low, it's a strong indication that your body's iron reserves are severely depleted. This is often seen as a red flag for iron deficiency anemia, as low ferritin levels suggest that not only is your circulating iron low, but your reserves for future use are also compromised.

While other tests like Serum Iron Levels and Total Iron-Binding Capacity (TIBC) provide valuable data on your body's current state of iron levels and usage, the Ferritin Test delves deeper into your body's long-term capacity to store and manage iron. This is particularly useful for understanding the severity of a deficiency and for planning longer-term treatment strategies.

Read our full article on How to Increase Ferritin Levels.

Transferrin Saturation Test

The Transferrin Saturation Test provides a specialized insight into your body's iron management system. Unlike other tests that measure iron levels or the body's ability to bind iron, this test specifically evaluates how well your body is utilising its iron-binding proteins, namely transferrin.

Transferrin is a blood protein tasked with carrying iron from your digestive tract to various tissues and organs that require it. The Transferrin Saturation Test calculates the percentage of transferrin molecules that are actively carrying iron, known as their saturation level. A low percentage generally points to iron deficiency, indicating that there is insufficient iron available for transferrin to carry.

This test is particularly beneficial when ordered alongside other core tests like Serum Iron Levels and Ferritin. The combination offers a well-rounded view of your immediate and long-term iron status, as well as your body's efficiency in transporting iron to where it is needed.

Additional Blood Tests for Iron

When iron deficiency anemia is suspected to be a symptom of another condition—such as gastrointestinal issues, celiac disease, or liver problems—specific tests for those conditions are required. For instance, C-Reactive Protein (CRP) Levels may be checked to measure inflammation, and Vitamin B12 and Folate Levels might be assessed to rule out other types of anemia.

Test Name Purpose Indicators of Other Contributing Conditions Normal Ranges
Hemoglobin Electrophoresis To identify various types of hemoglobin and related anemias Abnormal types of hemoglobin Adult Hemoglobin (HbA): 95-98%
Reticulocyte Count To measure the rate of production of new red blood cells Abnormally low or high reticulocyte count 0.5% to 2.5% of red cells
Liver Function Tests To assess the liver's health and its role in iron metabolism Abnormal liver enzyme levels ALT: 7-56 units per liter of blood; AST: 10-40 units/L
C-Reactive Protein (CRP) Levels To measure inflammation which can interfere with iron absorption Elevated CRP levels 0 to 1.0 mg/dL
Vitamin B12 and Folate Levels To assess for deficiencies that can also cause anemia Low Vitamin B12 or Folate levels Vitamin B12: 200-900 pg/mL; Folate: 2.7-17.0 ng/mL

Hemoglobin Electrophoresis Test

Hemoglobin Electrophoresis is a specialized test that expands the scope of anemia diagnostics by examining the diverse types of hemoglobin in your blood. While other tests focus primarily on iron levels and its transport mechanisms, this test delves into the structural aspects of hemoglobin, the protein responsible for carrying oxygen in the blood.

The test is particularly valuable for differentiating between various forms of anemia. While low iron levels could point to iron deficiency anemia, the presence of abnormal types of hemoglobin might suggest other conditions like thalassemia or sickle cell anemia.

Hemoglobin Electrophoresis is often recommended when initial tests like the Complete Blood Count (CBC) and Serum Iron Levels show anomalies that can't be readily explained by iron deficiency alone. The test can also be useful for those who have a family history of hemoglobinopathies or are of ethnic backgrounds where these conditions are more prevalent.

Reticulocyte Count Test

The Reticulocyte Count is a focused diagnostic tool that provides insights into the rate at which your bone marrow is producing new red blood cells. Unlike other tests that primarily measure existing levels or functionality of iron and hemoglobin, this test directly evaluates the efficacy of your body's red blood cell production mechanisms.

Reticulocytes are immature red blood cells, and their count serves as a reliable gauge of bone marrow activity. An elevated or reduced reticulocyte count can offer clues into underlying conditions that may be affecting your body's ability to produce red blood cells adequately. For instance, a low count might indicate that the bone marrow is not responding to a need for more red blood cells, which could be due to a range of factors, from nutritional deficiencies to more serious conditions like bone marrow disorders.

The Reticulocyte Count is often utilized in conjunction with other tests when iron deficiency anemia is either confirmed or suspected, but the cause remains elusive. It's also particularly useful in cases where treatment has been initiated, as it helps monitor the bone marrow's response to therapy.

Liver Function Tests

Liver function tests are important as the liver plays a role in iron metabolism. Abnormal results could signify an underlying liver condition that needs to be addressed.

C-Reactive Protein (CRP) Levels

This test measures the level of CRP, a marker of inflammation. High levels can indicate an underlying condition that may be contributing to anemia.

Vitamin B12 and Folate Levels

These nutrients are essential for red blood cell production, and deficiencies can also lead to anemia. These levels are typically checked to rule out other types of anemia.

Advanced Diagnostic Procedures for Testing Iron

After the initial blood tests, you might need further investigations, especially if the cause of your iron deficiency anemia remains unclear or if you fall into a severe or complex category. Let's delve into what these additional tests entail:

Peripheral Blood Smear

A peripheral blood smear involves examining a drop of your blood under a microscope. This helps to identify the size and shape of red blood cells, and it can reveal any abnormalities that might suggest a specific type of anemia or other blood disorder.

Specialised Tests for Severe Cases of Iron Deficiency

For those who have severe or complicated cases of iron deficiency anemia, additional diagnostic tools may be utilized to uncover underlying issues.

Bone Marrow Aspiration and Biopsy - Gold Standard for Diagnosing Iron Deficiency Anemia

In extreme cases, a bone marrow aspiration and biopsy may be performed. This is considered the gold standard for diagnosis, providing detailed information about your body's ability to produce red blood cells and revealing the level of iron stores in the bone marrow.

Endoscopic Examination

For those with symptoms of gastrointestinal bleeding, an endoscopic examination can be valuable. It allows healthcare professionals to directly view the digestive tract and identify issues like ulcers or tumors that may be contributing to iron loss.

Understanding the Interpretation of Test Results for Anemia

After you've undergone diagnostic tests for iron deficiency anemia, the next crucial stage is interpreting these results. Understanding the figures and their implications for your health is not straightforward, so it's important to consult healthcare professionals for detailed explanations tailored to your medical profile.

Various factors can affect the outcomes of your blood tests. For instance, the time of day when the test is conducted and your fasting status can impact the levels of specific markers such as serum iron. Underlying health conditions like liver disease or chronic inflammation are also critical to consider, as they can influence test results.