What Is Iron Deficiency Anemia?

Iron deficiency anemia is when your body does not have enough iron to produce hemoglobin—the protein in red blood cells that carries oxygen throughout the body. Iron is an essential mineral needed to make red blood cells, and low amounts can lead to anemia, causing headaches, pale skin, fatigue, and other symptoms.

Insufficient dietary intake of iron, blood loss, and certain medical conditions lead to iron deficiency anemia. Treatment varies depending on the cause but often involves dietary changes or supplements to increase your iron intake. 

Iron deficiency anemia is common, affecting 30% of the global population. Anyone can be affected, but it is most common in women and children.

Iron Deficiency Anemia Symptoms 

Mild iron deficiency anemia may not cause symptoms. Symptoms usually develop slowly and worsen over time due to reduced oxygen supply throughout your body. 

Common symptoms of iron deficiency anemia include:

• Fatigue or lack of energy 
• Shortness of breath or chest pain, especially during physical activity 
• Dizziness or lightheadedness 
• Headaches 
• Pale or yellowish skin 
• Cold hands and feet 
• Rapid heartbeat 
• Unexplained weakness 
• Pica (craving non-food items such as clay or ice) 
• Swollen or sore tongue 
• Hair loss
• Brittle nails 
  

What Causes Iron Deficiency Anemia? 

Iron deficiency anemia occurs when you do not have enough iron to produce hemoglobin. If your iron levels are low, your body will use iron reserves to produce healthy red blood cells. As your iron reserves deplete, fewer red blood cells are produced, leading to iron deficiency anemia.

Several factors can cause low iron, including inadequate iron intake through your diet, insufficient iron absorption, blood loss, and certain medical conditions. 

Inadequate Iron Intake 

Your body cannot produce iron, so it is important to eat iron-rich foods to maintain healthy iron levels. If your diet is lacking in iron-containing foods, you can become deficient. The amount of iron your body needs depends on age, sex, and whether you are pregnant or lactating. The recommended dietary allowance (RDA) of iron is:

• Infants 0-6 months: 0.27 mg 
• Infants 7-12 months: 11 mg
• 1-3 years: 7 mg 
• 4-8 years: 10 mg
• 9-13 years: 8 mg 
• 14-18 years: 11 mg (males), 15 mg (females)
• 19-50 years: 8 mg (males), 18 mg (females) 
• 51+ years: 8 mg 
  

The RDA for iron is 27 mg during pregnancy and 9-10 mg when breastfeeding. 

Problems Absorbing Iron

Certain medical conditions and medications can interfere with or impair iron absorption (malabsorption) and lead to iron deficiency anemia, including:

• Gastrointestinal conditions, such as Crohn's disease, celiac disease, ulcerative colitis, or an H. Pylori infection
• Surgery on your digestive system, such as bariatric (weight loss) surgery 
• Genetic conditions that impair iron absorption, such as cystic fibrosis 
• Medications used to treat heartburn, ulcers, and other acid-related conditions (e.g., proton-pump inhibitors, calcium carbonate, and histamine-2 receptor antagonists)

Blood Loss 

Your body loses iron when you bleed. Normally, your body makes new red blood cells (RBCs) after blood loss, but it can take 4-6 weeks for your body to replenish its RBC supply.

Common causes of blood loss associated with iron deficiency anemia include:

• Heavy menstruation 
• Internal bleeding in the gastrointestinal tract due to inflammatory bowel disease, colon cancer, or other GI disorders
• Bleeding during childbirth 
• Regular use of over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs), such as Advil (ibuprofen) or Aleve (naproxen)
• Traumatic injury or surgery 
• Urinary tract bleeding due to urinary tract infection (UTI)
  

Risk Factors

Iron deficiency anemia is common in people of all ages, but certain risk factors can increase the likelihood of developing the condition, such as:

• Following a vegetarian or vegan diet 
• Pregnancy, recent childbirth, and breastfeeding 
• Children who drink more than 16-24 ounces of cow's milk daily, which can impair iron absorption 
• Having a chronic inflammatory disease, such as heart failure or obesity

Diagnosis

To diagnose iron deficiency anemia, healthcare providers usually begin with a physical exam and review of your symptoms, medical history, and risk factors. Blood tests confirm the diagnosis and determine the severity of anemia.

A complete blood count (CBC) is a blood test used to confirm the diagnosis and determine the severity of anemia. A CBC measures the number, size, and shape of red blood cells and the amount of hemoglobin in the blood. A low hemoglobin level and smaller or paler red blood cells can indicate iron deficiency anemia.

Other blood tests that can point to iron deficiency include:

• Serum iron: Measures the amount of iron in the blood.
• Serum ferritin: Measures the amount of the protein ferritin, which stores iron in your body's cells. 
• Serum transferrin: Measures the amount of the protein transferrin, which transports iron throughout the body. High levels can indicate iron deficiency. 
• Peripheral blood smear: A blood sample is examined under a microscope to check the shape and size of red blood cells. Small or pale red blood cells can indicate iron deficiency.

If your healthcare provider suspects bleeding is the cause of your anemia, they may order additional testing, such as:

• Fecal occult blood test: Detects blood in the stool.
• Endoscopy: A tube with a camera is inserted into the mouth to look at the esophagus and stomach and look for abnormalities in the upper gastrointestinal tract. 
• Colonoscopy: A tube with a camera is inserted into the rectum to look at the colon to check for abnormalities (e.g., polyps) that can cause bleeding. 
• Pelvic examination: If you menstruate, a pelvic exam can help search for a source of bleeding. A pelvic ultrasound may be a part of this exam to visualize the uterus and bladder and determine the cause of heavy or abnormal menstrual bleeding. 
• Urine testing: To look for blood or hemoglobin in the urine.
  

Treatments for Iron Deficiency Anemia  

Treatment for iron deficiency anemia focuses on increasing your iron intake to replenish your body's iron stores. If an underlying condition, such as an ulcer or excessive menstrual bleeding, causes iron deficiency, treatment will involve managing the condition and stopping the bleeding. 

Treatment options for iron deficiency anemia may include making necessary dietary changes, taking iron supplements, getting iron intravenously, a blood transfusion, or a combination of these things.

Dietary Changes

Eating iron-rich foods can help restore iron levels in your body. Foods that contain iron include red meat, poultry, seafood, beans, leafy green vegetables, and fortified pasta and grains. Vitamin C can also help with iron absorption, so including foods such as citrus fruits, tomatoes, and bell peppers can be helpful.

Iron Supplements

Iron supplementation is a mainstay treatment for anemia. Your healthcare provider may recommend over-the-counter iron or prescribe iron supplements in liquid, tablet, or capsule form. They may recommend you take a vitamin C supplement with your iron to help improve iron absorption.

Intravenous (IV) Iron

If you have severe iron deficiency anemia, do not absorb iron well, or tolerate oral supplements, you may need intravenous (IV) iron. IV iron is administered in a healthcare setting (e.g., doctor's office) in one large dose or smaller doses given over several weeks.

Blood Transfusion

In severe cases of iron deficiency anemia, blood transfusions may be necessary to restore red blood cells quickly. Blood transfusions are usually reserved for people actively bleeding or with severe symptoms such as shortness of breath and chest pain. A blood transfusion doesn't fully correct the iron deficiency, so you will require other treatments to restore your iron levels.

Prevention

Preventing iron deficiency anemia involves making lifestyle choices that can help maintain healthy iron levels, including:

• Take iron supplements: If you have risk factors for iron deficiency anemia, your healthcare provider may recommend taking iron supplements. For some people, a multivitamin that includes iron is adequate.
• Treat the underlying cause: If you have an underlying condition associated with an increased risk of iron deficiency or experience heavy bleeding, work with your healthcare provider to properly manage the condition and prevent heavy bleeding. 
• Limit caffeine consumption: Coffee, tea, and other caffeinated beverages can inhibit iron absorption. 

Complications 

Untreated iron deficiency anemia can lead to health problems, such as:

• Heart problems: Your heart has to work harder than normal when anemic, which can lead to a rapid or irregular heartbeat. Over time, this can lead to heart failure. 
• Increased risk of infections: Iron deficiency anemia can weaken the immune system and increase the risk of infections.
• Pregnancy complications: Iron deficiency anemia during pregnancy can increase the risk of preterm delivery, low birth weight, and postpartum depression. 
• Growth and developmental delays: Children with severe or long-lasting iron deficiency anemia may experience stunted growth, developmental delays, and short attention spans.
• Cognitive impairment: Severe iron deficiency anemia may lead to cognitive impairment, including problems with memory, attention, and concentration.
• Restless legs syndrome: This is characterized by a strong urge to move your legs due to uncomfortable sensations in them.
  

Living With Iron Deficiency Anemia 

If you have iron deficiency anemia, you may feel weak and lack the energy to carry out your daily tasks. Managing iron deficiency anemia and your symptoms can be frustrating, so taking care of yourself physically and emotionally is important. 

Treatment for iron deficiency anemia can help replenish your iron stores; you should feel better within a few weeks, and your iron stores should be fully replenished within a few months. In the meantime, focus on eating a healthy, balanced diet, taking your supplements as prescribed, and resting when you can. Seek support from family and friends, and contact your healthcare provider if your symptoms are not improving with treatment.