Anemia

Medically Reviewed by Zilpah Sheikh, MD on August 04, 2023
10 min read

Anemia is defined as a low number of red blood cells. In a routine blood test, anemia is reported as a low hemoglobin or hematocrit. Hemoglobin is the main protein in your red blood cells. It carries oxygen and delivers it throughout your body. If you have anemia, your hemoglobin level will be low, too. If it is low enough, your tissues or organs may not get enough oxygen. Symptoms of anemia – like fatigue or shortness of breath – happen because your organs aren't getting what they need to work the way they should.

Anemia is the most common blood condition in the U.S. It affects almost 6% of the population. Women, young children, and people with long-term diseases are more likely to have anemia. Important things to remember are:

  • Certain forms of anemia are passed down through your genes, and infants may have it from birth.
  • Women are at risk of iron-deficiency anemia because of blood loss from their periods and higher blood supply demands during pregnancy.
  • Older adults have a greater risk of anemia because they are more likely to have kidney disease or other chronic medical conditions.

How serious is anemia?

There are many types of anemia. All have different causes and treatments. Some forms – like the mild anemia that happens during pregnancy – aren’t a major concern. But some types of anemia may reflect a serious medical condition.

Can anemia be cured?

Yes, anemia can be easily cured. It is usually a short-term issue that can be treated with a change in diet or by taking supplements. It is uncommon to need other interventions to treat anemia, but it is possible. 

The signs of anemia can be so mild that you might not even notice them. At a certain point, as your blood cells decrease, symptoms often develop. Depending on the cause of the anemia, symptoms may include:

  • Dizziness, lightheadness, or feeling like you are about to pass out
  • A fast or unusual heartbeat
  • A headache
  • Pain, including in your bones, chest, belly, and joints
  • Problems with growth, for children and teens
  • Shortness of breath
  • Skin that’s pale or yellow
  • Cold hands and feet
  • Tiredness or weakness

Severe anemia symptoms

If anemia gets worse, symptoms may include:

  • Brittle nails
  • Mouth ulcers
  • Loss of sexual interest
  • For women, increased menstrual bleeding
  • An inflamed or sore tongue
  • While at rest or with little activity, shortness of breath
  • Getting lightheaded when you stand up
  • Pale skin color
  • Pica syndrome, or the desire to eat non-food things such as ice
  • Blue color to the whites of the eyes

Symptoms of dying from anemia 

Dying from anemia is very rare. Some genetic conditions that could contribute to this include sickle cell and some hemolytic anemias being passed down. After a major injury, severe bleeding can lead to short-term, life-threatening anemia. And cancers and other diseases may also be a potential cause of anemia.

There are more than 400 types of anemia, and they’re divided into three groups:

  • Anemia caused by blood loss
  • Anemia caused by decreased or faulty red blood cell production
  • Anemia caused by destruction of red blood cells

Anemia caused by blood loss

You can lose red blood cells through bleeding. This can happen slowly over a long period of time, and you might not notice. Causes can include:

  • Gastrointestinal conditions such as ulcers, hemorrhoids, gastritis (inflammation of your stomach), and cancer
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen, which can cause ulcers and gastritis
  • A woman’s period, especially if you have a heavy menstruation (or heavy period). This can be linked to fibroids.
  • Post-trauma or post-surgery 
  • Blood loss at delivery and the immediate postpartum period

Anemia caused by decreased or faulty red blood cell production

With this type of anemia, your body may not create enough blood cells, or they may not work the way they should. This can happen because there’s something wrong with your red blood cells or because you don’t have enough minerals and vitamins for your red blood cells to form normally. Conditions linked to these causes of anemia include:

Bone marrow and stem cell problems may keep your body from producing enough red blood cells. Some of the stem cells in the marrow that’s in the center of your bones will develop into red blood cells. If there aren’t enough stem cells, if they don’t work right, or if they’re replaced by other cells such as cancer cells, you might get anemia. Anemia caused by bone marrow or stem cell problems includes:

  • Aplastic anemia happens when you don’t have enough stem cells or have none at all. You might get aplastic anemia because of your genes or because your bone marrow was injured by medications, radiation, chemotherapy, or infection. Other conditions that commonly affect the bone marrow include multiple myeloma and leukemia. Sometimes, there’s no clear cause of aplastic anemia.
  • Lead poisoning. Lead is toxic to your bone marrow, causing you to have fewer red blood cells. Lead poisoning can happen when adults come into contact with lead at work, for example, or if children eat chips of lead paint. You can also get it if your food comes into contact with some types of pottery that aren’t glazed right.
  • Thalassemia happens with a problem with hemoglobin formation (four chains aren't correctly formed). You make really small red blood cells, though you can make enough of them to be asymptomatic, or it can be severe. It’s passed down in your genes and usually affects people of Mediterranean, African, Middle Eastern, and Southeast Asian descent. This condition can range from mild to life-threatening; the most severe form is called Cooley's anemia.

Iron-deficiency anemia happens because you don’t have enough of the mineral iron in your body. Your bone marrow needs iron to make hemoglobin, the part of the red blood cell that takes oxygen to your organs. Iron-deficiency anemia can be caused by:

  • A diet without enough iron, especially in infants, children, teens, vegans, and vegetarians
  • Certain drugs, foods, and caffeinated drinks
  • Digestive conditions such as Crohn's disease, or if you’ve had part of your stomach or small intestine removed
  • Donating blood often
  • Endurance training
  • Pregnancy and breastfeeding using up iron in your body
  • Your period
  • A common cause is chronic slow bleed, usually from your digestive system.

Sickle cell anemia is a disorder that, in the U.S., affects mainly African Americans and Hispanic Americans. Your red blood cells, which are usually round, become crescent-shaped because of a problem in your genes. Anemia results when the red blood cells break down quickly, so oxygen doesn’t get to your organs. The crescent-shaped red blood cells can also get stuck in tiny blood vessels and cause pain.

Vitamin-deficiency anemia can happen when you aren’t getting enough vitamin B12 and folate. You need these two vitamins to make red blood cells. This kind of anemia can be caused by:

  • Dietary deficiency: If you eat little or no meat, you might not get enough vitamin B12. If you overcook vegetables or don’t eat enough of them, you might not get enough folate.
  • Megaloblastic anemia: When you don’t get enough vitamin B12, folate, or both
  • Pernicious anemia: When your body doesn’t absorb enough vitamin B12

Other causes of vitamin deficiency include medications, alcohol abuse, and intestinal diseases such as tropical sprue.

Anemia linked to other chronic conditions usually occurs in the setting of long-standing inflammation. Inflammatory proteins slow the bone marrow's production of young red blood cells in a variety of ways. Conditions that cause this type of anemia include:

Anemia caused by destruction of red blood cells

When red blood cells are fragile and can’t handle the stress of traveling through your body, they may burst, causing what’s called hemolytic anemia. You might have this condition at birth, or it could come later. Sometimes, the causes of hemolytic anemia are unclear, but they can include:

  • An attack by your immune system, as with lupus. This can happen to anyone, even a baby still in the womb or a newborn. That’s called hemolytic disease of the newborn.
  • Conditions that can be passed down through your genes, such as sickle cell anemia, thalassemia, and thrombotic thrombocytopenic purpura (TTP)
  • An enlarged spleen. This can, in rare cases, trap red blood cells and destroy them too early.
  • Something that puts strain on your body, such as infections, drugs, snake or spider venom, or certain foods
  • Toxins from advanced liver or kidney disease
  • Vascular grafts, prosthetic heart valves, tumors, severe burns, being around certain chemicals, severe hypertension, and clotting disorders

A complete blood count (CBC) test will measure your red blood cells, hemoglobin, and other parts of your blood. Your doctor will ask about your family history and your medical history after the CBC. They’ll probably do some tests, including:

  • Blood smear or differential to count your white blood cells, check the shape of your red blood cells, and look for unusual cells
  • Reticulocyte count to check for immature red blood cells

Your treatment will depend on your type of anemia. 

  • If you have aplastic anemia, you might need medication, blood transfusions (in which you get blood from another person), or a bone marrow transplant (in which you get a donor’s stem cells).
  • If you have hemolytic anemia, you might need medication that will hold back your immune system. Your primary care doctor may refer you to a doctor who specializes in vascular problems.
  • If it’s caused by blood loss, you might have surgery to find and fix the bleeding. If you have iron-deficiency anemia, you’ll probably need to take iron supplements and change your diet.
  • Sickle cell anemia treatment includes painkillers, folic acid supplements, intermittent antibiotics , or oxygen therapy. A drug called hydroxyurea (Droxia, Hydrea, Siklos) is often prescribed to decrease sickle cell pain crises (complicated mechanism). The medication called voxelotor (Oxbryta) can help your red blood cells keep their proper shape. Crizanlizumab-tmca (Adakveo) can keep blood cells from sticking together and blocking vessels. L-glutamine oral powder (Endari) can cut down on your trips to the hospital for pain and also guard against a condition called acute chest syndrome. 
  • If you have a vitamin B12 or folate deficiency, you will be prescribed supplements..
  • Thalassemia doesn’t usually need treatment, but if your case is severe, you might have blood transfusions, a bone marrow transplant, or surgery.

Anemia diet

To treat anemia, eat an iron-rich diet. If you don't eat enough iron, your body can become iron-deficient. Some foods that have high amounts of iron include:

  • Meats
  • Eggs
  • Leafy green veggies
  • Iron-fortified foods like cereals
  • Beans
  • Seafood
  • Peas
  • Nuts and dried fruit
  • Lentils

Anemia home remedies

Eating a diet with iron-rich foods is one way to treat your anemia at home. 

  • Anemia supplements. You can also take supplements, which will increase the amount of iron and hemoglobin in your body. Ferrous sulfate comes in liquid and tablet forms. Usually, the serving size is 325 milligrams. Talk to your doctor about taking an iron supplement for anemia and see how they recommend taking it. But typically, you'll want to take it on an empty stomach. Don't combine your supplement with milk, caffeine, or calcium supplements. It may help to increase absorption to take your supplement with vitamin C such as a glass of orange juice.

Anemia complications

Anemia can lead to severe tiredness, making it very hard to get through your day. It can also lead to an arrhythmia, or irregular heartbeat. Because there isn't as much oxygen in the blood, the heart must pump more, which could lead to heart failure. Anemia can even be fatal, especially if you lose a lot of blood too quickly. 

Anemia and Pregnancy

When you get pregnant, your body goes through many changes. Your body produces 20% to 30% more blood, which means you need more iron and vitamins.

A lot of people don't have enough iron for their second and third trimesters, which could lead to anemia. While mild anemia is normal during pregnancy, severe anemia could put your baby at risk for anemia as well.

If you're severely anemic during your first two trimesters, you're at a higher risk of having a preterm delivery or a baby with a low birth weight.

People who are pregnant and anemic are also at a higher risk of blood loss during labor and may have a harder time fighting infections.

During pregnancy, you need 27 milligrams of iron each day. You can take prenatal vitamins that contain iron to help prevent or treat an iron deficiency during pregnancy. Your doctor might also give you a different iron supplement.

You can also eat more iron-rich foods to help with your iron deficiency.

If you do these things and still have anemia, your doctor might suggest testing to find other potential causes. If your anemia is due to iron deficiency, they'll have you take more iron supplements. But if you had a history of gastric bypass, small bowel surgery, or you aren't able to take an iron supplement, your doctor will give you iron through an IV (intravenous) needle.