Anemia: symptoms, causes, types, treatment

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Ashley Abramson 

Felix Gussone, MD - Contributor Avatar

Reviewed by Felix Gussone, MD, Ro, 

Written by Ashley Abramson 

last updated: Aug 24, 2021

5 min read

Everyone gets dizzy or lightheaded from time to time, whether from standing up too fast or skipping breakfast. That feeling, in itself, does not mean that you have anemia. Similarly, we all know what it feels like to doze off during the day after a night of tossing and turning in bed. Uncomfortable as these common experiences are, they usually don’t pose a major threat to your health. 

But if your symptoms of dizziness or fatigue don’t go away for a while, and they include other symptoms like shortness of breath, there could be another issue at play. Here’s what you need to know about anemia, a common condition brought on by a lack of red blood cells.


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What is anemia? 

Anemia is a condition in which people lack enough healthy red blood cells they need to carry oxygen to the body’s organs. It can cause some uncomfortable and even serious symptoms, and is always a sign of another underlying medical condition. 

Anemia is fairly common. Researchers estimate that a third of the global population suffers from anemia. The condition particularly affects young children and pregnant women: 42% of children less than five years of age and 40% of pregnant women worldwide are anaemic (Chaparro, 2019, Auerbach, 2016).

What causes anemia?

There are a few main causes of anemia, all of them leading to a lack of healthy red blood cells (Badireddy, 2021):

  • Blood loss, like from an injury, gastro-intestinal bleed, or heavy or irregular menstrual cycle

  • Lack of blood cell production, usually from another health condition

  • Red blood cell destruction, usually because of another health condition

While one specific factor might be to blame for someone’s anemia, that’s not always the case. Sometimes, anemia — particularly, chronic anemia — can stem from more than one issue (Badireddy, 2021).

Types of anemia

There are several kinds of anemia, and each type causes a person’s red blood cells to decrease. Below are some of the most common types of anemia: 

Iron-deficiency anemia

One common cause of anemia is an iron deficiency (DeLoughery, 2016). The body needs iron to make hemoglobin, a protein found in red blood cells that’s responsible for carrying oxygen to tissue. When a person doesn’t have enough iron in their body, they might not have enough hemoglobin and healthy red blood cells to carry oxygen through their body. 

Iron-deficiency anemia most commonly occurs due to blood loss from menstrual periods and gastrointestinal bleeding (DeLoughery, 2016). It can also happen when someone doesn’t consume enough iron in their diet.

Vitamin-deficiency anemia 

The body also needs certain nutrients to produce red blood cells. Without ample nutrients, the body may not be able to produce enough healthy cells to transport oxygen. Folate deficiency, which involves low levels of vitamin B9, can cause anemia. 

A vitamin B12 deficiency can also cause a type of anemia known as pernicious anemia. People who eat vegan diets might be at a higher risk for vitamin-deficiency anemia, since meat and dairy are major sources of vitamin B12 (Larpin, 2019). 

Anemia of inflammation 

Sometimes, other diseases can cause anemia. Anemia of inflammation, sometimes called anemia of chronic disease, happens when inflammatory proteins present interfere with red blood cell production. Inflammatory conditions that can cause inflammatory anemia include (Fraenkel, 2016):

  • Obesity 

  • Kidney failure

  • Cancer

  • Chronic infection

  • Autoimmune disease

Hemolytic anemia 

Hemolytic anemia occurs when red blood cells are destroyed faster than the body can replace them. Commonly, hemolytic anemia occurs due to autoimmune disease, in which the immune system destroys its own cells or tissues (Phillips, 2018). 

Aplastic anemia 

Aplastic anemia happens when the body’s bone marrow simply can’t make enough red blood cells, often due to an infection or autoimmune disease (Wang, 2019).

Sickle cell anemia 

Sickle cell anemia is a hereditary disease that causes red blood cells to have an abnormal, crescent-like shape. These abnormal blood cells die before the body can use them, which can cause a shortage of red blood cells (Sedrak, 2021). 

Anemia symptoms

Often, anemia is mild enough that it doesn’t have any symptoms at all. Whether symptoms arise ultimately depends on the cause and severity of anemia, and whether a person has any other illnesses. For example, heart disease often results in more severe anemia (Turner, 2021). 

Common symptoms of anemia include (Baldwin, 2020):

  • Weakness

  • Lethargy

  • Dizziness

  • Headaches

  • Shortness of breath

  • Arrhythmias (irregular heartbeat)

One study also links iron-deficiency anemia to migraines (Pamuk, 2016).

Anemia can obviously make people uncomfortable, but discomfort isn’t the only negative effect. Anemia has also been associated with negative outcomes like increased morbidity and mortality, decreased work productivity, and impaired neurological development (Chaparro, 2019).

For all these reasons, if you think you might have anemia, bring it up to your healthcare provider. A medical professional can help you figure out what’s going on, along with suggesting ways to fix the underlying problem and manage your symptoms in the process.

Anemia risk factors 

Certain risk factors might make a person more likely to experience anemia. These groups of people may be more likely to be anemic: 

  • Older people (Marton, 2020)

  • People with heart failure (Chopra, 2020)

  • People with high inflammation markers (Chopra, 2020)

  • Pregnant women (Turner, 2021)

  • Women of reproductive age (Turner, 2021)

These risk factors might make a person more likely to develop anemia, but not everyone with anemia falls within these groups. If you have symptoms of anemia, make sure to talk to your healthcare provider. 

Getting diagnosed with anemia 

To diagnose anemia, a healthcare provider usually starts with a routine exam and a blood test known as a complete blood count (CBC). If your CBC shows lower-than-normal numbers in any of these categories, you might have anemia (Turner, 2021): 

  • Hemoglobin (the concentration of hemoglobin in all of your blood)

  • Hematocrit (the percent of blood volume red blood cells occupy)

  • Red blood cell count (the number of red blood cells in a specified amount of blood)

Once your healthcare provider identifies you have anemia, they’ll attempt to figure out why. So along with your blood test, your healthcare provider will also want to know about your health history and lifestyle. 

Your family history, the severity of your symptoms, when they started, and any pre-existing conditions can help your provider understand why you might be anemic. In general, the lower the hemoglobin, the higher the risk for an underlying disease (Goddard, 2011). Further lab tests might also be necessary. 

It’s worth noting that certain factors, like intense physical activity, pregnancy, and old age can also cause low red blood cells (Turner, 2021).

Anemia treatment

There’s no cure-all treatment for anemia because while it results in the same symptoms, not everyone’s anemia has the same cause. So, ultimately, how a healthcare provider treats anemia depends on what’s at the bottom of it. For example, for someone with anemia from low iron or folate, taking daily iron supplements or folic acid supplements might be enough to improve symptoms.  

In severe cases of iron deficiency anemia, or when other treatments aren’t working, healthcare providers might recommend intravenous iron to restore hemoglobin levels (DeLoughery, 2016). If a person has anemia from another illness, a healthcare provider will also treat the underlying disease (Madu, 2017). 

Anemia prevention

It’s not always possible to prevent anemia. That said, healthy lifestyle choices can help boost your overall health, and even protect you from anemia in some cases.

Adequate nutrition can reduce the odds of nutrition-related anemia in some people (Bianchi, 2015).  Aim to eat foods rich in iron, folate, and vitamin B12. If your healthcare provider has identified you’re low in any of these, or if you’re worried about getting anemia, nutritional supplements may be helpful (Turner, 2021).

While anemia is very common, it can also cause uncomfortable, even serious symptoms. Luckily, anemia is fairly easy to treat when a medical provider can find the underlying issue. If you think you may be anemic, seek out medical care. Your provider can diagnose the problem and, depending on the cause of the anemia, find the right treatment. 


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

August 24, 2021

Written by

Ashley Abramson

Fact checked by

Felix Gussone, MD

About the medical reviewer

Felix Gussone is a physician, health journalist and a Manager, Medical Content & Education at Ro.