What are the signs and symptoms of iron deficiency?

By Jennifer Scheinman MS RDN Jun 16, 2023 • 5 min

Feeling tired? We've all been there. Not getting enough sleep may not be the only reason for this lack of energy, though. It could be that you're missing out on a key mineral from your diet—iron. Iron deficiency is the most common cause of anemia (a type of blood disorder), which can cause fatigue.

As the name suggests, iron deficiency anemia occurs when you don't have enough iron in your blood. For some people with a mild to moderate iron deficiency, signs may be mild. However, over time the symptoms may become more noticeable as anemia becomes more severe.

What is iron and what causes iron deficiency?

Iron is a mineral found in many foods we eat. It’s found naturally in some foods, like lean beef, oysters, poultry, lentils, beans, tofu, cashews, potatoes and spinach. Grain products, such as breakfast cereals and breads, and infant formulas are often fortified with iron.

The body uses iron to make hemoglobin, a protein in red blood cells that transports oxygen from the lungs to other parts of the body, and myoglobin, a protein that provides the muscles with oxygen. The body also needs iron to make certain hormones.

If you do not take in enough iron, your body will use iron it has stored in the muscles, liver, spleen and bone marrow. But once those levels fall too low, you can develop iron deficiency anemia. In most cases, iron deficiency anemia is caused by getting too little iron through your diet. However, it may also occur due to blood loss or conditions that make it difficult for your body to absorb iron.

What are the signs and symptoms of an iron deficiency?

In the early stages of an iron deficiency, you may not have any noticeable symptoms. When iron deficiency anemia develops, red blood cells become smaller and contain less hemoglobin. This causes less oxygen to reach your organs, and it may cause symptoms. These may include:

  • Extreme fatigue or tiredness. This is the most common symptom. People tend to be more run-down than usual and may not have enough energy to get through the day.
  • Weakness
  • Difficulty concentrating
  • Irritability
  • Headache
  • Dizziness
  • Cold hands or feet
  • Pale skin
  • Brittle nails or spooning of the nails (depression in the nails where they appear scooped out)
  • Sore or swollen tongue
  • Cracks on the sides of the mouth
  • Faster than normal heart rate
  • Shortness of breath
  • Restless legs syndrome, a condition that causes an uncomfortable feeling in the legs and an uncontrollable desire to move them
  • Pica, a condition characterized by intense cravings for nonfood items, such as ice or dirt
  • Poor appetite, especially in infants and children.
  • Who is at risk of an iron deficiency?
The following groups of people are at higher risk of developing iron deficiency and iron deficiency anemia:
  • Infants and young children
  • Pregnant women
  • Women of reproductive age and women who have heavy menstrual periods
  • People who donate blood often
  • People with certain health conditions, including colon and other types of cancer, digestive disorders and heart failure
  • People who follow a vegetarian or vegan diet

How is an iron deficiency diagnosed and treated?

Only a healthcare provider can diagnose an iron deficiency. They will review your health history and give you an exam. They will likely do blood tests to check the amount of hemoglobin and iron in your blood. Your provider may also order other tests to determine the cause of the deficiency.

Treatment for an iron deficiency will depend on its cause and severity. Eating more iron-rich foods, taking iron supplements or, in more severe cases, having certain procedures may be part of your treatment plan. Always talk to your healthcare provider first before you take any supplements.

When left untreated, iron deficiency anemia can cause severe complications and may even be life-threatening. If you have symptoms of anemia or are concerned about your risk, talk to your healthcare provider.

Clinically reviewed and updated June 2023.

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