Anemia occurs when you have a level of red blood cells (RBCs) in your blood that is lower than normal. Iron deficiency anemia is the most common type of anemia, and it occurs when your body doesn’t have enough of the mineral iron. Your body needs iron to make a protein called hemoglobin. This protein is responsible for carrying oxygen to your body’s tissues, which is essential for your tissues and muscles to function effectively. When there isn’t enough iron in your blood stream, the rest of your body can’t get the amount of oxygen it needs.
While the condition may be common, a lot of people don’t know they have iron deficiency anemia. It’s possible to experience the symptoms for years without ever knowing the cause.
In women of childbearing age, the most common cause of iron deficiency anemia is a loss of iron in the blood due to heavy menstruation or pregnancy. A poor diet or certain intestinal diseases that affect how the body absorbs iron can also cause iron deficiency anemia. Doctors normally treat the condition with iron supplements or changes to diet.
According to the American Society of Hematology, iron deficiency is the most common cause of anemia. There are many reasons why a person might become deficient in iron. These include:
Inadequate iron intake
Eating too little iron over an extended amount of time can cause a shortage in your body. Foods such as meat, eggs, and some green leafy vegetables are high in iron. Because iron is essential during times of rapid growth and development, pregnant women and young children may need even more iron-rich foods in their diet
Pregnancy or blood loss due to menstruation
In women of childbearing age, the most common causes of iron deficiency anemia are heavy menstrual bleeding and blood loss during childbirth.
Certain medical conditions can cause internal bleeding, which can lead to iron deficiency anemia. Examples include an ulcer in your stomach, polyps (tissue growths) in the colon or intestines, or colon cancer. Regular use of pain relievers, such as aspirin, can also cause bleeding in the stomach.
Inability to absorb iron
Certain disorders or surgeries that affect the intestines can also interfere with how your body absorbs iron. Even if you get enough iron in your diet, celiac disease or intestinal surgery, such as gastric bypass, may limit the amount of iron your body can absorb.
Anemia is a common condition and can occur in both men and women of any age and from any ethnic group. Some people may be at greater risk for iron deficiency anemia than others. These include:
- women of childbearing age
- pregnant women
- people with poor diets
- people who donate blood frequently
- infants and children, especially those born prematurely or experiencing a growth spurt
- vegetarians who don’t replace meat with another iron-rich food
If you’re at risk for iron deficiency anemia, talk to your doctor to determine if blood testing or dietary changes could benefit you.
The symptoms of iron deficiency anemia can be very mild at first, and you may not even notice them. According to the American Society of Hematology (ASH), most people don’t realize they have mild anemia until they have a routine blood test.
The symptoms of moderate to severe iron deficiency anemia include:
- general fatigue
- pale skin
- shortness of breath
- strange cravings to eat items that aren’t food, such as dirt, ice, or clay
- a tingling or crawling feeling in the legs
- tongue swelling or soreness
- cold hands and feet
- fast or irregular heartbeat
- brittle nails
A doctor can diagnose anemia with blood tests. These include:
Complete blood cell (CBC) test
A complete blood cell (CBC) test is usually the first test a doctor will use. A CBC test measures the amount of all components in the blood, including:
- red blood cells (RBCs)
- white blood cells (WBCs)
The CBC test provides information about your blood that is helpful in diagnosing iron deficiency anemia. This information includes:
- the hematocrit level, which is the percent of blood volume that is made up of RBCs
- the hemoglobin level
- the size of your RBCs
A normal hematocrit range is 34.9 to 44.5 percent for adult women and 38.8 to 50 percent for adult men. The normal range for hemoglobin is 12.0 to 15.5 grams per deciliter for an adult woman and 13.5 to 17.5 grams per deciliter for an adult man. In iron deficiency anemia, the hematocrit and hemoglobin levels are low. Also, RBCs are usually smaller in size than normal.
A CBC test is often performed as part of a routine physical examination. It’s a good indicator of a person’s overall health. It may also be performed routinely before a surgery. This test is useful to diagnose this type of anemia since most people who have an iron deficiency don’t realize it.
Anemia can usually be confirmed with a CBC test. Your doctor might order additional blood tests to determine how severe your anemia is and help determine treatments. They may also examine your blood through a microscope. These blood tests will provide information including:
- iron level in your blood
- RBC size and color
- RBCs are pale in color if they’re deficient in iron.
- ferritin levels
- Ferritin is a protein that helps with iron storage in your body. Low levels of ferritin indicate low iron storage.
iron-binding capacity (TIBC)
- Transferrin is a protein that transports iron. A TIBC test is used to determine the amount transferrin that’s carrying iron.
Tests for internal bleeding
If your doctor is concerned that internal bleeding is causing your anemia, additional tests may be needed. One test you may have is fecal occult test to look for blood in your feces. Blood in your feces may indicate bleeding in your intestine.
Your doctor may also perform endoscopy, in which a small camera on a flexible tube is used to view the linings of your gastrointestinal tract. An EGD test (upper endoscopy) allows a doctor to examine the lining of the esophagus, stomach, and the upper part of the small intestine. A colonoscopy (lower endoscopy) allows a doctor to examine the lining of the colon, the lower portion of the large intestine. These tests can help identify sources of gastrointestinal bleeding.
Pregnancy, significant menstrual bleeding, and uterine fibroids are all reasons why women are more likely to experience iron deficiency anemia.
Heavy menstrual bleeding occurs when a woman bleeds longer or more than women typically bleed during menstruation. According to the Centers for Disease Control and Prevention (CDC), typical menstrual bleeding lasts for four to five days and the amount of blood lost ranges from 2 to 3 tablespoons. Women with excess menstrual bleeding typically bleed for more than seven days and lose twice as much blood as normal.
According to the National Heart, Lung, and Blood Institute (NHLBI), an estimated 20 percent of women of childbearing age have iron deficiency anemia. Pregnant women are even more likely to experience iron deficiency anemia because they require greater amounts of blood to support their growing babies.
A pelvic ultrasound can be used to look for the source of excess bleeding during a woman’s period, such as fibroids. Like iron deficiency anemia, uterine fibroids often don’t cause symptoms. However, they occur when muscular tumors grow in the uterus. While they’re not usually cancerous, they can commonly cause heavy menstrual bleeding that can lead to iron deficiency anemia.
Most cases of iron deficiency anemia are mild and don’t cause complications. The condition can usually be easily corrected. However, if anemia or iron deficiency is untreated, it can lead to other health problems, including:
Rapid or irregular heartbeat
When you’re anemic, your heart has to pump more blood to make up for the low amount of oxygen. This can lead to irregular heartbeat. In severe cases, it can lead to heart failure or an enlarged heart.
In severe cases of iron deficiency, a child may be born prematurely or with a low birth weight. Most pregnant women take iron supplements as part of their prenatal care to prevent this from happening.
Delayed growth in infants and children
Infants and children who are severely deficient in iron may experience a delay in their growth and development. They may also be more likely to experience infections.
Iron tablets can help restore iron levels in your body. If possible, you should take iron tablets on an empty stomach, which helps the body absorb them better. If they upset your stomach, you can take them with meals. You may need to take the supplements for several months. Iron supplements may cause constipation or stools that are black in color.
Diets high that include the following foods can help treat or prevent iron deficiency:
- red meat
- dark green, leafy vegetables
- dried fruits
- iron-fortified cereals
Additionally, vitamin C helps your body absorb iron. If you’re taking iron tablets, a doctor might suggest taking the tablets along with a source of vitamin C, like a glass of orange juice or citrus fruit.
Treating the underlying cause of bleeding
Iron supplements won’t help if excess bleeding causes the deficiency. A doctor may prescribe birth control pills to women who have heavy periods. This can reduce the amount of menstrual bleeding each month.
In the most severe cases, a blood transfusion can replace iron and blood loss quickly.
When caused by inadequate iron intake, iron deficiency anemia can be prevented by eating a diet high in iron-rich foods and vitamin C. Mothers should make sure to feed their babies breast milk or iron-fortified infant formula.
Foods high in iron include:
- meat, such as lamb, pork, chicken, and beef
- pumpkin and squash seeds
- leafy greens, such as spinach
- raisins and other dried fruit
- seafood, such as clams, sardines, shrimp, and oysters
- iron-fortified dry and instant cereals
Foods high in vitamin C include:
- citrus fruits, such as oranges, grapefruits, strawberries, kiwis, guavas, papayas, pineapples, melons, and mangoes
- red and green bell peppers
- Brussels sprouts
- leafy greens
If you experience symptoms of iron deficiency anemia, talk to your doctor. Self-diagnosing and self-treating iron deficiency anemia can result in adverse health effects due to too much iron in your blood. The complications from too much iron in your blood include liver damage and constipation.