Anemia is a common condition caused by a lack of healthy red blood cells. Learn more about anemia symptoms, causes, types, and potential treatments.
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Anemia occurs when your body doesn’t have enough healthy red blood cells (RBCs) or enough hemoglobin. Hemoglobin is an iron-containing protein found in your red blood cells that carries oxygen.
People with anemia often develop fatigue and weakness due to their tissues not getting enough oxygen. Anemia has many potential causes, including nutrient deficiencies, genetic conditions, and complications of some medications. The most common type is caused by low iron.
Anemia is the most common hematologic (blood) disorder in the United States. Once the underlying cause is identified, many types are treatable with dietary changes or medical therapy. Seek medical attention if you suspect you have anemia to get a proper diagnosis and understand how to best treat it.
Symptoms of anemia mainly occur if your tissues aren’t getting enough oxygen. Common symptoms of anemia include:
Fatigue, tiredness, general weakness
Shortness of breath
Lightheadedness or dizziness
Pale skin
Difficulty concentrating
Cold hands or feet
Prolonged and untreated anemia may lead to complications, such as:
Mood changes
Chest pain
Lower leg cramps with exercise
Fainting
Confusion
Heart failure
Some types of anemia may cause additional symptoms. For example, hemolytic anemia may cause jaundice, a yellowing of the skin and eyes. Jaundice is often more difficult to see on darker skin tones than on lighter skin tones.
Anemia can be divided into subtypes depending on the underlying cause. Here are the most common types of anemia.
Iron-deficiency anemia is the most common type of anemia. It occurs when your body lacks enough iron to produce adequate hemoglobin.
Iron-deficiency anemia is often caused by not getting enough iron in your diet, but other factors can contribute to its development, such as:
Digestive conditions that impair iron absorption
Blood loss, especially in older adults
Parasitic infections, especially in developing countries
Vitamin-deficiency anemia is caused by low levels of folic acid (folate) or vitamin B12. These two B vitamins play a critical role in the production of new red blood cells.
Like iron-deficiency anemia, it can be caused by low dietary intake of these nutrients or conditions that impair your ability to absorb them.
Sickle cell anemia or sickle cell disease is a condition where your red blood cells are shaped like sickles. Normally, they’re round with an indent in the center.
It’s an inherited condition that’s particularly common among people of African, Middle Eastern, and Mediterranean descent. In the United States, 90 percent of cases occur in people of African descent.
Hemolytic anemia is a group of conditions where RBCs are destroyed faster than bone marrow can replace them. It’s caused by a mix of inherited and non-inherited conditions, including:
Sickle cell disease or thalassemia
Hereditary spherocytosis or elliptocytosis, conditions that cause abnormally shaped red blood cells
Enzyme defects, such as G6PD deficiency or pyruvate kinase deficiency
Autoimmune hemolytic anemia (where your immune system attacks RBCs)
Microangiopathic hemolytic anemia, where blood cells become damaged in your small blood vessels
Paroxysmal nocturnal hemoglobinuria or other genetic conditions
Some toxins, infections, or drugs
Aplastic anemia is when your bone marrow stops making an adequate number of new red blood cells. It can be caused by genetic disorders or acquired conditions that develop throughout your life. In about 75 percent of cases of acquired aplastic anemia, the underlying cause isn’t clear. Known causes include:
Toxin exposure, including some pesticides, arsenic, and benzene
Radiation therapy or chemotherapy
Medications used to treat some autoimmune diseases, such as lupus and rheumatoid arthritis
Infectious diseases, such as hepatitis or Epstein-Barr infection
Leukemia or another cancer that has spread to your bone marrow
Anemia of chronic disease is caused by inflammation linked to chronic diseases, such as:
Kidney disease
Rheumatoid arthritis
Crohn’s disease
Liver disease
Long-standing infections
Sideroblastic anemia is a group of conditions where your body produces too many abnormal red blood cells. These abnormal cells are engorged with iron molecules and impair your body’s ability to use iron.
Sideroblastic anemia can be caused by inherited genetic conditions or acquired conditions like high alcohol consumption or heavy metal toxicity.
Each type of anemia has its own risk factors.
People at the highest risk of iron-deficiency anemia include those who:
Have heavy menstrual periods
Are pregnant or were recently pregnant
Have recently undergone surgery or physical trauma
Have gastrointestinal diseases that affect iron absorption, like celiac disease
Have stomach ulcers, are on anti-acid therapies, or have had a gastric bypass
Follow a vegetarian or vegan diet
Drink large amounts of cow’s milk daily
Have conditions that cause blood loss or donate blood frequently
Engage in high-endurance physical activity
Risk factors for vitamin B12-deficiency or folate-deficiency anemia can include:
Metformin use
Not eating animal products
Having a condition that impairs nutrient absorption
Recently undergoing stomach surgery
Pernicious anemia, an autoimmune condition that impairs vitamin B12 absorption
People with a family history of sickle cell anemia are at an increased risk of developing it too. People of African descent are at the highest risk in the United States.
Risk factors for hemolytic anemia can include:
A family history of associated autoimmune disorders
Associated infections like malaria
Taking medications like antibiotics or antimalarials if you have glucose-6-phosphate dehydrogenase (G6PD) deficiency
An associated genetic condition
Risk factors for aplastic anemia include:
Regular exposure to radiation, pesticides, or benzene
Having a viral infection like hepatitis or HIV
Some autoimmune diseases, like lupus
Taking associated medications like some anti-epileptic drugs, chemotherapy, or antibiotics
People at the highest risk of anemia of chronic disease are those with chronic conditions that cause inflammation, such as rheumatoid arthritis or chronic kidney disease.
By extension, risk factors for these conditions, such as having other autoimmune diseases, are also risk factors for anemia of chronic disease.
Risk factors for sideroblastic anemia include:
Unhealthy alcohol use
Copper deficiency
Zinc toxicity
Certain medications, such as isoniazid or chloramphenicol
Family history
Your healthcare provider may want to test you for anemia if you have symptoms like fatigue or weakness. Along with considering your symptoms, they’ll also likely review your medical history and perform a physical exam. During a physical exam, they’ll look for characteristic signs of anemia, such as:
Pale skin
Rapid heart rate or irregular rhythm
An enlarged liver or spleen, which they may be able to feel through your abdomen
Some types of anemia, such as sickle cell anemia, might be discovered during routine blood testing, often during newborn screening.
The main test for diagnosing anemia and finding out what type of anemia you have is a blood test. Blood tests you might receive include:
Complete blood count (CBC)
Reticulocyte count
Peripheral blood smear
Iron studies
Vitamin B12 and folate levels
Hemoglobin and hematocrit tests
Because lab values can vary, an abnormal result is often repeated or followed by further studies to confirm the diagnosis.
In some cases, you may also need other tests to monitor complications or rule out other conditions, such as:
Bone marrow biopsy
Kidney or liver function tests
Gastrointestinal evaluation, such as a fecal occult blood test or an endoscopy
Here’s a look at the treatment options for the most common types of anemia.
The best treatment for iron-deficiency anemia depends on the underlying cause. Your treatment plan might include:
Oral iron supplements
Dietary changes to include more iron-rich foods, especially from animal sources
Treating the underlying cause of blood loss, such as a stomach ulcer
Iron therapy administered intravenously in severe cases
Low testosterone levels can contribute to mild anemia in some older men. Research suggests testosterone therapy may improve red blood cell production in men with confirmed hypogonadism and anemia. However, TRT is not an approved treatment for anemia itself. It’s usually only considered after a healthcare professional confirms you have low testosterone and rules out other causes of anemia. As many as 15 percent of older men with low testosterone experience anemia.
You can talk to a healthcare professional about TRT for low T, and if you’re eligible, receive a prescription through our telehealth service, no in-person visit needed.
Treatment options for anemia related to vitamin B deficiencies may include:
High-dose oral B12 dietary supplements
Daily oral folate tablets
Dietary improvements, like eating more meat, eggs, and dairy for a vitamin B12 deficiency or broccoli and Brussels sprouts for a folic acid deficiency
Treating underlying gastrointestinal conditions
The first-line treatment for sickle cell anemia is usually the oral medication hydroxyurea. Other treatments may include:
Blood transfusions for severe anemia
Bone marrow or stem cell transplant, a new and potentially curative treatment usually performed in children with severe complications
Over-the-counter or prescription pain medications
Treatment for hemolytic anemia can include:
Treating the underlying cause, like an infection
Stopping a certain medication
Immunosuppressive therapy
Blood transfusions, in severe cases
Splenectomy, in some chronic or severe autoimmune cases
Treatment options for aplastic anemia include:
Blood transfusions and platelet transfusions as supportive care
Immunosuppressive therapy
Bone marrow or stem cell transplant
The primary treatment for anemia of chronic disease is treating the underlying cause. You may also receive supportive treatments such as blood transfusions.
Sideroblastic anemia has a wide range of causes, so treatment can also vary widely. Some options include:
Pyridoxine (Vitamin B6) supplementation
Avoiding alcohol or certain drugs
Blood transfusions for severe anemia
Iron chelation therapy, to prevent iron overload from transfusions
Treating underlying causes, like zinc toxicity
Anemia has many potential causes. Some are preventable and others aren’t. You may be able to reduce your chances of developing some types of anemia by:
Eating a balanced diet that includes plenty of iron, B12, and folate
Monitoring for signs of gastrointestinal bleeding, such as blood in your feces, and getting any necessary treatment as soon as possible
Avoiding excessive use of NSAIDs or medications that may injure the gastrointestinal tract
Managing chronic diseases properly
Receiving treatment for conditions that affect nutrient absorption, like Crohn’s disease
Avoiding excessive alcohol use
Getting regular checkups and blood tests, especially for older adults or those with risk factors
Anemia is characterized by not having enough red blood cells or hemoglobin to properly carry oxygen throughout the body. The most common cause in the United States is iron-deficiency anemia. It may be caused by low iron intake or problems with iron absorption.
People with anemia often develop symptoms such as unexplained fatigue or weakness. It’s important to seek medical attention promptly if you believe you may have anemia. Your healthcare provider can help you figure out whether you have anemia, which type you may have, and how to best treat it.
For men with low testosterone, studies suggest testosterone therapy may improve mild anemia by stimulating red blood cell production. If you have symptoms of low testosterone or anemia, talk to a licensed medical provider through our telehealth service to discuss whether TRT may be right for you.
Iron-deficiency anemia is the most common type of anemia. If you have iron-deficiency anemia, your doctor may recommend increasing the amount of iron you get in your diet or taking an iron supplement.
Hemoglobin cutoffs for anemia depend on age and sex. In adult males, a hemoglobin concentration of less than about 13.5 g/dL is often considered anemia.
As the name suggests, vitamin B12-deficiency anemia is caused by low vitamin B12 or an inability to properly use all the vitamin B12 in your body, leading to large, immature red blood cells (megaloblastic anemia). Iron-deficiency anemia is caused by low iron or an inability to utilize all of your dietary iron.
Severe anemia may cause chest pain. This is because your heart has to work harder to supply oxygen to your tissues. People with coronary artery disease or who are at risk of heart disease may have worse anemia symptoms. Seek medical attention if you experience chest pain.
Mild anemia may not cause symptoms or may cause relatively minor symptoms like increased fatigue. More severe anemia can pose serious risks, including heart failure, arrhythmias, and compromised oxygen delivery to vital organs.
Many forms of anemia are treatable or manageable. Nutrient-deficiency anemias often resolve with supplementation and diet. Inherited or chronic types may require lifelong monitoring and treatment and may not be curable.
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