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Red blood cells are disc-shaped blood cells that carry oxygen to the organs and tissues of your body. Anemia happens when the number of healthy red blood cells in your body is too low.

Every part of your body needs a sufficient supply of oxygen to function effectively. Many of the symptoms of anemia, such as fatigue and shortness of breath, are caused by decreased oxygen delivery to your body’s vital organs and tissues.

Red blood cells contain an iron-rich protein called hemoglobin. Hemoglobin binds to oxygen in your lungs, allowing red blood cells to carry and deliver it throughout your body. Anemia is measured according to the amount of hemoglobin in your blood.

It’s estimated that anemia affected more than 1.74 billion people around the world in 2019. Women and people with chronic diseases such as cancer have a higher risk of developing anemia.

There are many different types and causes of anemia. Some types of anemia are mild and can be easily treated, while others can cause potentially serious health complications.

This article will take a dive deeper into the different causes, symptoms, and nutritional factors associated with anemia, and will also explain how it’s diagnosed and treated.

Red blood cells are produced in your bone marrow and have an average lifespan of 100 to 120 days. On average, your bone marrow produces 2 million red blood cells each second while approximately the same number are removed from circulation.

About 1 percent of your red blood cells are removed from circulation and replaced each day.

Any process that has a negative effect on this balance between red blood cell production and destruction can cause anemia.

Causes of anemia are generally divided into those that decrease red blood cell production and those that increase red blood cell destruction or loss.

Factors that decrease red blood cell production

When red blood cell production is lower than normal, more red blood cells are leaving your body than entering circulation. This can potentially lead to anemia.

Factors that decrease red blood cells production can be divided into two categories – acquired and inherited.

Acquired factors that can decrease RBC production include:

Some types of genetic (inherited) conditions are also associated with a decrease in production of healthy red blood cells. These include:

  • Fanconi anemia
  • Schwachman-Diamond syndrome
  • Diamond-Blackfan anemia
  • dyskeratosis congenita
  • amegakaryocytic thrombocytopenia

Factors that increase red blood cell destruction or loss

On the other hand, anything that causes destruction or loss of red blood cells at a rate faster than they’re made can also cause anemia.

Factors that increase the destruction of red blood cells can also be either acquired or inherited.

Some acquired factors that may lead to increased red blood cell destruction or loss are:

Some inherited causes of increased red blood cell destruction can include:

There are certain factors that may increase your risk of developing anemia. These include:

Many of the symptoms of anemia are associated with a lack of oxygen being supplied to the body’s organs and tissues. If you have anemia, you may experience symptoms like:

Other symptoms that may happen with some types of anemia include:

If you have signs or symptoms of anemia, it’s important to get medical attention, especially if you experience fainting or chest pain.

Iron-deficiency anemia

Iron-deficiency anemia is the most common type of anemia and happens when you’re not getting enough iron. It’s estimated that 50 percent of all anemias are due to a deficiency in iron.

A variety of factors can contribute to lower levels of iron in your body, including:

  • blood loss
  • getting less than the recommended daily amount of iron in your diet
  • having a health condition that can make absorption of iron more difficult, such as having IBD or a previous gastric bypass surgery

Many people with mild or moderate iron-deficiency anemia have no symptoms. In these individuals, anemia is often detected during routine blood tests.

Severe iron-deficiency anemia can cause symptoms that can include, but are not limited to:

  • fatigue
  • shortness of breath
  • chest pain

When left untreated, this type of anemia can cause potentially serious complications.

Vitamin-deficiency anemia

Vitamin-deficiency anemia is caused by having lower than normal levels of folate or vitamin B12. This type of anemia is typically due to low dietary intake of these nutrients.

In addition to some of the general symptoms of anemia, some signs that anemia may be caused by low folate levels can include:

  • soreness of your mouth and tongue
  • color changes in your skin, hair, or nails

Pernicious anemia is a specific type of anemia that’s caused by low levels of vitamin B12. Individuals with pernicious anemia often lack a protein that’s made in the stomach called intrinsic factor. Intrinsic factor helps your body absorb vitamin B12 from your diet. In some instances, the small intestine also has trouble absorbing vitamin B12.

Anemia due to lack of vitamin B12 also shares many common anemia symptoms. Some symptoms more specific to deficiency in vitamin B12 include:

Hemolytic anemia

In hemolytic anemia, red blood cells are destroyed faster than your body can replace them. There are many different causes of hemolytic anemia, including:

In addition to general anemia symptoms, some additional symptoms that are more specific to hemolytic anemia include:

Aplastic anemia

Aplastic anemia happens when your bone marrow does not produce enough red blood cells. It’s caused by damage to stem cells in the bone marrow that would normally go on to develop into red blood cells. Because of this damage, fewer red blood cells are made.

Aplastic anemia is most commonly caused by autoimmune activity, during which your immune system attacks stem cells in the bone marrow. Other potential causes include certain medications, exposure to toxins, and inherited genetic changes.

Aplastic anemia also has an impact on the production of white blood cells and platelets. So in addition to a low red blood cell count, people with this type of anemia also have low counts of white blood cells and platelets.

A low white blood cell count can lead to frequent infections, while low levels of platelets can cause easy bruising or bleeding. Other potential symptoms of aplastic anemia include skin rashes and nausea.

Anemia of inflammation or chronic disease

Anemia of inflammation or chronic disease happens because of underlying health conditions that cause inflammation in the body. It’s believed that the effects of this inflammation may change the way your body works. For example, people with this type of anemia may:

  • have low levels of iron in the blood, despite having a high amount of stored iron
  • produce less erythropoietin, a hormone that’s made in the kidneys and stimulates red blood cell production
  • have bone marrow that doesn’t respond well to erythropoietin
  • have red blood cells that have a lifespan that’s shorter than normal, meaning they die faster than they’re replaced

Many different health conditions can cause anemia of inflammation or chronic disease. Some examples include, but are not limited to:

Daily requirements for vitamins and iron vary according to sex and age.

Women need more iron and folate than men because of iron loss during menstrual periods and fetal development during pregnancy.

Iron

According to the National Institutes of Health, the recommended daily iron intake for adults ages 19 to 50 are as follows:

For men8 mg
For women18 mg
During pregnancy27 mg
While breastfeeding9 mg

People over age 50 require only 8 milligrams (mg) of iron daily. A supplement may be needed if adequate iron levels can’t be acquired through diet alone.

Good sources of dietary iron include:

  • chicken and beef liver
  • dark turkey meat
  • red meats, such as beef
  • seafood
  • fortified cereals
  • oatmeal
  • lentils
  • beans
  • spinach

Folate

Folate is the form of folic acid that occurs naturally in the body.

People over age 14 require 400 micrograms of dietary folate equivalents (mcg/DFE) per day.

If you’re pregnant or breastfeeding, the recommended intake increases to 600 mcg/DFE and 500 mcg/DFE per day, respectively.

Examples of foods rich in folate are:

  • beef liver
  • lentils
  • spinach
  • great northern beans
  • asparagus
  • eggs

You can also add folic acid to your diet with fortified cereals and breads.

Vitamin B12

The daily adult recommendation for vitamin B12 is 2.4 mcg. If you’re pregnant, you need 2.6 mcg per day, and if you’re breastfeeding, you need 2.8 mcg daily, according to the NIH.

Beef liver and clams are two of the best sources of vitamin B12. Other good sources include:

  • fish
  • meat
  • poultry
  • eggs
  • other dairy products

Vitamin B12 is also available as a supplement for those who don’t get enough from their diet.

Need a supplement?

If you know you have anemia, or aren’t getting enough of the above nutrients, get your boost by shopping for supplements online:

Before taking any supplements, talk to your healthcare professional to make sure the supplements you want to take are safe for you.

A diagnosis of anemia begins with both your health history and your family health history, along with a physical exam.

A family history of certain types of anemia such as sickle cell disease can be helpful. A history of exposure to toxic agents in the home or workplace might point to an environmental cause.

Laboratory tests are most often used to diagnose anemia. Some examples of tests that your doctor may order include:

  • Complete blood count (CBC). The CBC blood test measures your hemoglobin levels and can show the number and size of red blood cells. It can also indicate if levels of other blood cells like white blood cells and platelets are normal.
  • Reticulocyte count. A reticulocyte count is a blood test that measures levels of immature red blood cells called reticulocytes. It can help your doctor determine if your bone marrow is producing enough new red blood cells.
  • Serum iron levels. A serum iron test is a blood test that measures the total amount of iron in your blood. It can show if iron deficiency is the cause of anemia.
  • Ferritin test. A ferritin test is a blood test that analyzes iron stores in your body.
  • Vitamin B12 test. The vitamin B12 test is a blood test that measures your vitamin B12 levels and helps your doctor determine if these levels are too low.
  • Folic acid test. A folic acid test is a blood test that measures your folate levels and can indicate if this level is too low.
  • Coombs test. The Coombs test is a blood test that looks for the presence of autoantibodies that are targeting and destroying your own red blood cells.
  • Fecal occult blood test. This test applies a chemical to a stool specimen to see if blood is present. If the test is positive, it means that blood is being lost somewhere in the gastrointestinal tract. Health conditions like stomach ulcers, ulcerative colitis, and colon cancer can cause blood in stool.
  • Bone marrow tests. Testing of a bone marrow aspirate or biopsy can help your doctor see if your bone marrow is functioning normally. These types of tests can be very helpful if conditions like leukemia, multiple myeloma, or aplastic anemia are suspected.

If left untreated, anemia can go on to cause potentially serious complications. These can include:

To avoid potential complications, it’s important to see your doctor if you develop signs or symptoms of anemia. In many situations, anemia can be easily treated.

Treating anemia depends on what’s causing it.

For example, if your anemia is caused by an underlying health condition, your doctor will work with you to treat that specific condition. Often, this can help improve anemia.

Anemia caused by inadequate intake of dietary iron, vitamin B12, or folate may be treated with nutritional supplements. In some cases, injections of B12 may be needed if it isn’t absorbed properly from the digestive tract.

Your doctor or a nutritionist may work with you to prescribe a diet that contains the appropriate amounts of vitamins, minerals, and other nutrients that may be lacking in your current diet.

In some cases, if anemia is severe, doctors may use drugs called erythropoiesis-stimulating agents to increase red blood cell production in the bone marrow. These drugs work in a similar way to the hormone erythropoietin, which your kidneys naturally produce.

If severe bleeding occurs or hemoglobin levels are very low, a blood transfusion may be necessary. During a blood transfusion, you’ll receive blood donated by an individual who has a matching blood type.

The long-term outlook for anemia depends on the cause and the response to treatment. Anemia is often very treatable, but it can cause serious complications if it’s left untreated.

The outlook for anemia due to deficiencies in iron or vitamins is typically good, provided you receive timely replacement of these important nutrients.

Going forward, it’s important to pay attention to your diet to ensure that you’re getting the recommended daily amounts of iron, folate, and vitamin B12. It may also be helpful to consider taking a daily multivitamin.

For anemia due to other causes, the outlook can vary. It’s possible that you’ll need long-term treatment to manage your anemia or the underlying health conditions that cause it.

Talk with your doctor about what to expect in your individual situation, including if you’re considering supplementation and whether it’s right for you.

Anemia is when you have low levels of red blood cells in your body. When this happens, your organs and tissues have a harder time getting oxygen. As a result, you may experience symptoms like fatigue, weakness, and shortness of breath.

Your body removes millions of red blood cells from circulation each day, replacing them with new ones. When this process is disrupted, it can cause anemia. For example, anemia can happen if the production of red blood cells is reduced or if these blood cells are destroyed or lost earlier than normal.

One of the more common causes of anemia is not getting enough nutrients like iron, folate, or vitamin B12. However, anemia can also be caused by blood loss and a wide variety of underlying health conditions.

Anemia can cause serious complications if it’s left untreated. That’s why it’s important to talk with a healthcare professional if you have symptoms of anemia. They can give you a proper diagnosis, determine the cause, and develop a treatment plan that’s right for you.