Anemia is a blood condition that causes general feelings of malaise. People with anemia feel weak and tired and may have difficulty breathing. They may also develop headaches or feel dizzy for no apparent reason.

Anemia is caused by a lack of oxygen-producing red blood cells or the body’s inability to use these cells. Long-term, the condition can cause respiratory or heart problems, such as an irregular heartbeat. Anemia can also be a sign of more severe health problems, such as internal bleeding, kidney disease and cancer.

The Centers for Disease Control and Prevention (CDC) estimates that 2.8 million people have anemia in the U.S. The disease caused 623,000 hospital visits in 2020, and it led to 5,987 deaths in 2021. Anemia can be a serious and complicated illness, but it is treatable in most cases.

What causes anemia?

People develop anemia for different reasons. In some cases, acute conditions could be responsible for a red blood cell deficiency, while dietary choices, medication and habits could also play a role.

Even if the anemia develops due to chronic conditions or genetics, dietary and lifestyle choices can impact the severity of symptoms.

Here’s a closer look at the different causes of anemia.

Nutritional deficiencies

The World Health Organization (WHO) lists iron deficiencies as the most common nutritional cause of anemia. People without enough iron-rich foods, such as red meat, fish and leafy greens may develop anemia. A lack of folate, B vitamins or vitamin A can also cause the condition. People with deficiencies may be able to use supplements to get the necessary nutrients to reverse the condition.

Chronic diseases

The American Society of Hematology suggests that people with certain chronic diseases have a higher risk of anemia. These illnesses include rheumatoid arthritis, other similar autoimmune diseases, kidney and liver disease, thyroid conditions and some cancers.

Blood loss

Bleeding from a wound or internal injury can cause a loss of red blood cells. Anemia develops when the body can’t replace the depleted cells fast enough. In some instances, doctors can provide a blood transfusion to reverse the damage.

Genetic disorders

Some people inherit red blood cell deficiencies. For instance, for example, those with sickle cell anemia are unable to form normal hemoglobin proteins and people with thalassemia do not produce enough hemoglobin. These conditions are genetic and may be present regardless of dietary factors or acute injuries.

Medications

Some medications can cause anemia. Studies have linked medicines used to treat high blood pressure with low hemoglobin production, and several classes of medication can cause hemolytic anemia. The culprits can include certain antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs).

Pregnancy

Pregnant women produce a higher volume of blood. More iron and vitamins are needed to maintain the proper ratio of red blood cells and hemoglobin. Patients can make dietary changes to treat pregnancy-induced anemia. Anemia is not abnormal or cause for concern during pregnancy unless red blood cell counts are extremely low.

Chronic infections

Anemia can develop in patients with chronic infections. Inflammation associated with these illnesses is the primary cause. The condition can develop because of bacterial, viral, fungal or parasitic infections. Autoimmune disorders like rheumatoid arthritis and lupus can also lead to anemia.

Alcoholism

People with alcoholism may suffer from premature destruction of red blood cells. They are also more prone to bacterial infections or other conditions causing anemia. Finally, in severe cases, alcoholism can lead to internal bleeding, and the body struggles to replace the lost hemoglobin.

What types of anemia are there?

There are eight types of anemia. It’s important to understand the differences because the most effective treatment varies depending on the variety. Some patients may have a higher risk due to genetics. For instance, people of certain ethnicities have a greater chance of developing hereditary anemia.

Here are the different anemia varieties.

Iron-deficiency anemia

Some patients lack sufficient iron. Iron deficiency anemia can develop because of an imbalanced diet, blood loss, internal bleeding or kidney disease. Children and pregnant women have higher risk factors for developing this anemia variety.

Vitamin-deficiency anemia

The body needs vitamins B9, also known as folate, and B12 for blood health. The body still produces red blood cells if it lacks these nutrients. However, the cells are abnormally large and contain low hemoglobin amounts.

Anemia of chronic disease

Anemia of chronic disease is due to inflammation caused by certain illnesses. The most common culprits are chronic kidney disease, autoimmune conditions like lupus, untreated or untreatable infections, or cancer. Even though the body has sufficient iron, the inflammation traps it in the tissue. It does not enter the bloodstream where it can create hemoglobin.

Aplastic anemia

Aplastic anemia involves low red blood cell counts due to bone marrow damage. The marrow cannot produce enough red blood cells, leading to anemia. This condition is common in people with marrow-related illnesses, exposure to certain toxins, or cancer. Cancer treatments like radiation can also cause aplastic anemia.

Hemolytic anemia

On average, red blood cells live for 120 days, and normally-functioning bodies will create replacement cells on that schedule. People with hemolytic anemia lose red blood cells before 120 days, and the lack of ready replacements creates a deficiency.

Patients can acquire this anemia type from medications or illnesses, or they can inherit it at birth. Older adults, Black people, people of Asian descent and men are more prone to this type of anemia.

Sickle cell anemia

Sickle cell anemia is an inherited genetic disorder. People with the condition have abnormal crescent or sickle-shaped red blood cells that block normal blood flow, causing cardiovascular issues and episodes of pain, known as pain crises.

Anyone can inherit sickle cell anemia. However, it’s more common in people of African, Hispanic, Asian, Mediterranean or Middle Eastern descent.

Thalassemia

Thalassemia is another form of inherited anemia. This disease stunts hemoglobin production, leading to chronic tiredness and weakness. Patients can define their risk factors by looking at their parents’ and grandparents’ medical histories.

Pernicious anemia

Pernicious anemia is an acquired condition with the same causes as other vitamin-deficient forms of anemia. While diet can cause this disease, it is also possible for people to develop pernicious anemia if they have conditions that prevent them from absorbing B vitamins.

What are the symptoms of anemia?

Anemia produces different symptoms. In some cases, these may be mild, while others may be more severe and lead to further complications.

Common symptoms include:

• Fatigue and weakness: Many people with anemia report lacking energy, feeling tired without reason or being unable to perform physical tasks. 
• Headache: People with anemia experience frequent headaches. Chronic head pain is often the first sign of a problem. 
• Rapid or irregular heartbeat: A patient’s heart rate may increase as the organ pumps faster to make up for the lack of oxygen in the blood. In addition to faster beating, patients can have arrhythmia, or an irregular heartbeat. 
• Cold hands and feet: Since their tissue does not get enough oxygen, people with anemia often feel cold. This symptom is especially evident in extremities like hands and feet. 
• Chest pains: People with moderate to severe anemia may experience chest pains or feelings of pressure or squeezing in their chest. 
• Pale skin: The lack of hemoglobin can cause pale skin in some people and jaundice (yellow-hued skin) in others. 
• Shortness of breath and dizziness: Anemia can cause shortness of breath when performing everyday actions like climbing stairs, walking, or getting out of bed.

Those with untreated anemia can weaken the immune system and make patients more prone to other infections or illnesses.

How does anemia impact certain populations?

Certain groups have a higher risk of developing anemia because of genetics, activities, diet, or age. Here is how anemia affects certain demographic populations.

Anemia in children

20% of children will develop anemia during their youth. Risk factors include poor diet, chronic illnesses, trauma or surgery, and early use of cow’s milk instead of formula or breast milk.

Symptoms can be mild or non-existent in many cases, though some children may experience fatigue, unexplained dizziness or shortness of breath while playing. Routine blood tests can reveal childhood anemia. In mild cases, dietary changes and supplements can eliminate symptoms.

Anemia in women

Because of increased blood volume, women can experience anemia during pregnancy. Pregnant women need up to 50% more iron than usual. Prenatal vitamins and supplements often contain additional iron to meet the body’s increased demand.

Also, many women who are menstruating have an increased risk of developing anemia due to blood loss. Routine blood tests can check iron, hemoglobin and red blood cell counts and supplements or dietary changes, such as eating beef or leafy greens, can help limit or eliminate symptoms.

Anemia in older adults

Aging patients are prone to anemia because of chronic diseases or vitamin deficiencies. Anemia due to chronic disease is the most common cause of the condition in older adults.

Vitamin and mineral supplements and dietary changes can alleviate symptoms, while treatment of underlying conditions, if possible, can also lessen the impact of anemia of chronic disease.

Anemia in vegetarians and vegans

Researchers found that vegetarians and vegans are more likely to have iron deficiencies. However, the findings varied by location, suggesting that people from some countries and cultures get iron and B vitamins from certain foods available locally.

While it may be possible to get necessary nutrients from other food sources, vegans and vegetarians can also take supplements to increase iron levels in the blood.

Anemia in athletes

Athletes with heavy training loads may experience iron-deficiency anemia. This condition is due to increased plasma volume in response to extended exertion. Iron also gets lost through sweat and because of natural inflammation caused by strenuous activity.

In addition to iron-rich foods and supplements, athletes can perform non-weight-bearing, low-intensity exercises to reduce the premature rupturing of red blood cells.

Can you prevent anemia?

Some forms of anemia are preventable through diet, supplements and a healthy lifestyle. Hereditary forms of the disease may be unavoidable, though you can take steps to reduce severity and symptoms.

Nutrition and diet

An iron-rich diet can prevent anemia related to nutrient deficiencies. In addition to consuming foods like beef, poultry, leafy greens, legumes and other dishes rich in iron, B12 and folate, you need to eat items with nutrients, to promote mineral absorption.

Iron amounts vary by age and gender, with recommendations falling between seven and 15 mg per day. Pregnant women need up to 27 mg.

Iron supplements

Those who don’t get enough iron from their diet can take a supplement to get the recommended daily amount. It is important to avoid taking too much iron. The upper limits are 40 to 45 mg per day, depending on age.

Treating underlying medical conditions

Infections, immune system diseases, and conditions causing inflammation can lead to anemia. Treating these chronic conditions will reduce the risk of developing co-morbidities like anemia.

Blood transfusions

In some cases, patients experiencing blood loss may get a transfusion to replace red blood cells lost to internal or external bleeding. This treatment is also common for people who already have anemia.

Avoiding certain medications

Antibiotics, NSAIDs, and other anti-inflammatory medications increase the risk of developing anemia by interfering with red blood cells, iron absorption and hemoglobin production.

Occasionally, antibiotic use is necessary to treat life-threatening infections. Patients can still monitor red blood cell and hemoglobin levels during treatment to ensure they don’t develop anemia.

How is anemia diagnosed?

Different laboratory tests can give physicians the information they need to make an accurate anemia diagnosis.

• Hemoglobin tests offer insights into general health and can detect anemia. Healthy hemoglobin ranges are 14 to 18 grams per deciliter for men and 12 to 16 grams per deciliter for women.
• Hematocrit is the percentage by volume of red blood cells and platelets. In the average patient, the test should reveal 45% red blood cells. A hematocrit test is one of the most common ways to detect anemia. 
• Complete blood count (CBC) offers data on white and red blood cells and platelets. Though you can book a blood test to look for anemia, doctors often order a CBC as part of regular health checkups. 
• A peripheral blood smear is a blood sample smeared on a glass slide and treated with a stain to reveal red and white blood cells. It is an inexpensive option and provides an accurate picture of cell ratios. 
• Iron studies, also known as iron tests, can help diagnose anemia and provide insights into the variety of anemia. 
• Tests to measure vitamin B12 and folate levels can provide insight into deficiencies in these vital nutrients. These tests can help doctors decide if a lack of B vitamins is causing the anemia. 
• A bone marrow biopsy can reveal aplastic anemia. This test is more invasive than a standard blood draw because it involves extracting samples from the inside of a bone.
• Kidney function tests, genetic tests and stool tests can reveal anemia indicators and other conditions that could increase your risk for developing anemia.

A doctor specializing in anemia can decide which tests are necessary and read the lab results to detect anemia or risk factors that could lead to its development.

How is anemia treated?

Most forms of anemia are treatable. According to the NIH, people with mild anemia may not need additional treatment provided they adjust their diet and use supplements appropriately. Here are the most effective treatments for this blood condition.

• Dietary changes are sufficient for reversing mild or moderate anemia caused by iron or vitamin deficiencies. Meat, fish, legumes and greens contain the necessary nutrients. 
• Vitamin supplements and iron supplements can ensure proper nutrient levels in people who are not able to consistently ingest enough iron and B vitamins through their diet. 
• Blood transfusions can add red blood cells and platelets to patients with deficiencies due to blood loss or some forms of hereditary anemia. 
• Treatment often focuses on iron or vitamin supplements, but doctors can prescribe erythropoiesis-stimulating agents (ESAs) to spur hemoglobin production in patients taking certain medications or suffering from chronic illnesses.

Anemia is a common comorbidity, meaning it occurs with other illnesses. Doctors can cure or lessen the impact of anemia of chronic disease or other similar forms by treating the underlying condition and adjusting the patient’s diet or taking other fundamental anemia treatment steps.

Additional anemia resources

Here are resources for additional information about anemia:

• The American Society of Hematology covers all varieties of blood-related conditions. 
• USAID’s Advancing Nutrition Initiative focuses on using nutrition to control diet-related conditions.
• The National Institute of Health Guide to Anemia offers insights and publishes information about anemia-related research.

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