menu iconknow your dna logosearch icon
What Is Anemia — Causes, Symptoms, Treatment & Other Types
Updated on January 31, 2024
Back to top
back to top icon
At Home Health
What Is Anemia — Causes, Symptoms, Treatment & Other Types

Anemia is a blood condition where you suffer a low count of healthy red blood cells (RBCs). Anemia dramatically lowers hemoglobin, the protein that helps transport oxygen.

Symptoms can range from mild to severe. It can also be temporary (acute) or long-term. Some common anemia symptoms are fatigue, lack of energy, and shortness of breath. 

“Mild anemia can be silent. Most cases can go undetected unless a routine blood exam is taken. But as the body loses more hemoglobin, more symptoms can develop,” says Dr. Rizza Mira.

That said, there are many types of anemia—each with its own symptoms and treatments. So we asked general practitioner Dr. Rizza Mira about the most common types. 

What Causes Anemia (Low RBC Count)

The body needs good functioning RBCs to perform its duties. They carry hemoglobin—the protein that delivers oxygen from the lungs to your body organs.1  

There are several health conditions that can affect your RBC count and lead to anemia. Its three primary causes are:

1. Loss of Blood

Iron deficiency is the leading cause of anemia. This condition often happens when you lose a significant amount of blood.

As you lose blood, your body fills your blood vessels with water from the tissues outside the bloodstream. But the added water dilutes your blood and decreases the RBC count.2

Acute blood loss can be short-term, such as during childbirth, surgery, or trauma. But it can also be long-term and last for months or years.

Dr. Mira says that during acute blood loss, symptoms can appear right away. However, this may not be the case for chronic anemia:

“Chronically, iron deficiency may not show symptoms because the body is already used to this low hemoglobin state.”

Anemia from long-term blood loss is often a result of health problems like:

  • Stomach ulcers
  • Gastrointestinal (GI) problems
  • Endometriosis
  • Heavy menstrual bleeding
  • Cancer
  • Other types of tumors

A study shows that prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen increases your chances of getting GI problems, like ulcers.3

Dr. Mira says these medications make the stomach prone to bleeding. In turn, they can reduce your RBC count.3

2. Destruction of Red Blood Cells

The RBC has a life cycle of 120 days. However, your body may destroy them in the bloodstream before they even reach their life span.

Autoimmune diseases like hemolytic anemia can cause your immune system to attack your RBCs and result in premature destruction.4 

3. Low RBC Production

Your bone has a soft, spongy tissue in its center called the bone marrow. The bone marrow produces stem cells that evolve into the RBCs, white blood cells (WBCs), and platelets.5

Bone marrow diseases can lead to leukemia — a type of bone marrow cancer.6 It prompts your body to produce excessive and abnormal WBCs, which can disrupt your RBC production.

Anemia can also happen due to bone marrow problems. Aplastic anemia is a form of anemia that occurs when your marrow has very few to zero stem cells.7

Thalassemia is another blood disorder that can cause anemia. It prevents red blood cells from maturing as they should.8 

“As a result, the red blood cells are not in the best condition to carry oxygen. This is what leads to anemic symptoms,” Dr. Mira explains.


Common causes of anemia:

  • Loss of blood - Losing a substantial amount of blood can dilute your blood and lessen the number of RBCs.
  • Destruction of red blood cells - Some diseases can fast-track the destruction of RBCs.
  • Low red blood cell production - Problems with your bone marrow can hamper the creation of RBCs.

Know Your DNA Reviews

Best DNA Kit

Don't miss out on the opportunity to learn more about yourself. Read our best DNA test page to find the best one for you.

Different Types of Anemia & Signs You Have Them

Anemia has different forms. Your signs can show up at birth, or you may acquire them over time. The cause behind the anemia defines its type.

What Is Iron Deficiency Anemia?

Iron deficiency anemia is the most common type of anemia. An insufficient amount of iron in the blood affects the formation of hemoglobin. 

Hemoglobin is the part of RBC that allows iron molecules to deliver oxygen from the lungs to your different body organs. They also collect carbon dioxide and bring them back to the lungs. 

Diets low in iron, blood loss, and GI problems that affect iron absorption are common causes of iron deficiency anemia.9

Symptoms of Iron Deficiency Anemia

You may experience mild symptoms of anemia at first, which can go unnoticeable. They can progress if you leave them untreated for an extended period. 

You can watch out for these common signs of iron deficiency anemia.

  • Tiredness
  • Chills
  • Shortness of breath
  • Lack of energy
  • Chest pain
  • Difficulty concentrating
  • Pale skin
  • Dizziness
  • Bruises
  • Headaches
  • Restless legs syndrome

What Is Vitamin Deficiency Anemia?

Vitamin deficiency anemia happens when you don’t get enough vitamins B12 (cobalamin) and B9 (folic acid) from your diet or if you have a condition that impairs their absorption in the gut.

Without these vitamins, your body can’t make enough healthy RBCs.10 Dr. Mira says they help form the structure and shape of red blood cells.

Instead, your body will produce abnormally large RBCs that don’t function properly. This is called megaloblastic anemia.

Vitamin Deficiency Anemia Symptoms

  • Extreme fatigue
  • Low energy
  • Pins and needles (paraesthesia)
  • A sore and red tongue
  • Mouth ulcers
  • Weak muscles
  • Blurry vision
  • Confusion
  • Problems with memory, understanding, and judgment

What Is Sickle Cell Anemia?

Sickle cell anemia or sickle cell disease (SCD) is a form of a genetic blood disorder. If you have this anemia, your hemoglobin will look like sickles instead of round, flexible discs.11  

Because of this abnormal shape, the RBCs cannot carry hemoglobin to the cells. Sickle cells are also sticky and stiff, which can obstruct your blood flow. 

Sickle Cell Anemia Symptoms

You can inherit sickle cell anemia from your parents, so it can be present at birth. But the symptoms may appear later when you’re around 6 months of age. 

The signs of sickle cell anemia include:

  • Swollen hands and feet
  • Frequent infections
  • Delay in growth and puberty
  • Problems with vision

You might also feel sudden pain in your back, chest, stomach, legs, arms, or knees each time blood flow is obstructed in these areas.

What Is Hemolytic Anemia?

Hemolytic anemia is a blood disorder defined by a short RBC life span. It means your body breaks the RBCs down sooner than replenishing them.12

You have a higher chance of developing this anemia if you have hereditary or autoimmune conditions. Meanwhile, other people acquire it from certain infections or medications.

Hemolytic Anemia Symptoms

Each person may show different symptoms. The most common signs are:

  • Pale skin
  • Jaundice (e.g., yellow skin, eyes, and mouth)
  • Dark-colored urine
  • Fever
  • Weakness
  • Dizziness
  • Confusion
  • Enlarged spleen and liver
  • Rapid heart rate
  • Heart murmur

What Is Aplastic Anemia

Aplastic anemia is a rare blood condition where the bone marrow stops producing new blood cells, including RBCs. It can develop over time or occur suddenly.

It can be inherited or acquired later in life. Factors that can cause aplastic anemia include viruses, immune system problems, medications, and exposure to toxic chemicals.

Aplastic Anemia Symptoms

“Aplastic anemia affects all cell lines — RBCs, WBCs, and platelets. This can lead to infection and bleeding,” says Dr. Mira.

Your symptoms depend on which blood cell is abnormally low.7 A low RBC count has the following symptoms:

  • Fatigue
  • Shortness of breath
  • Dizziness
  • Pale skin
  • Chest pain

Infections and fever are signs of a low WBC count. Meanwhile, a person with a low platelet count may bruise or bleed easily and become more prone to nosebleeds. 

What Is Thalassemia?

Thalassemia is a hereditary blood disorder that causes your body to produce fewer healthy RBCs and hemoglobin. It has two main types — alpha and beta thalassemia.

Your body needs alpha globin and beta globin to make red blood cells. Not having enough of these proteins can affect your RBC’s ability to carry oxygen to the tissues.

You can develop thalassemia when you inherit a mutated gene that affects your hemoglobin. 

Thalassemia Symptoms

The symptoms of thalassemia depend on the type and how severe your condition is. Some people won’t show any signs. Others may take years before they notice anything.

Signs of thalassemia are:

  • Wide or brittle bones
  • Enlarged spleen
  • Fatigue
  • Weakness
  • Pale or yellow skin
  • Dark urine
  • Poor appetite


Types of anemia:

  • Iron deficiency anemia (IDA)
  • Vitamin deficiency anemia
  • Sickle cell anemia
  • Hemolytic anemia
  • Aplastic anemia
  • Thalassemia

Common Symptoms of Anemia

Tiredness, shortness of breath, and pale skin occur in all types of anemia. Other symptoms that you may experience include:

  • Dizziness
  • Lack of energy
  • Headache
  • Sore tongue
  • Fast heartbeat

How to Test for Anemia (Low Red Blood Cells)

The primary lab test for ruling out anemia is a complete blood count (CBC). It checks the count of your RBCs, along with their size and shape. 

However, your doctor may order more tests based on your symptoms.

For example, blood and urine tests can help diagnose hemolytic anemia. A bone marrow biopsy can also identify specific types of anemia.

Some blood tests can assess whether your body has inadequate vitamins B12 and folate. Meanwhile, serum ferritin can show how much iron your body has.

A peripheral blood smear is also needed to determine the type of anemia. Diagnosing your anemia and its cause helps your doctor decide which treatments to give you. 

How is Anemia Treated?

The treatment for anemia depends on its cause. Different treatments are available: 

  • Iron deficiency anemia (IDA): Can be treated with an iron-rich diet and oral iron supplements. But a blood transfusion may be needed if there’s acute blood loss.
  • Vitamin deficiency anemia: Treatment includes eating more foods or taking dietary supplements containing folic acid and vitamin B12.
  • Sickle cell anemia: Treated with folic acid supplements, antibiotic medications, or oxygen therapy. Painkillers may also help relieve pain.
  • Hemolytic anemia: Treatment may include immunosuppressants.
  • Aplastic anemia: Your treatment options are medications, blood transfusions, and a bone marrow transplant. The surgery will include a donor’s stem cells.
  • Thalassemia: Can benefit from a bone marrow transplant. A blood transfusion is also necessary in some cases.

Know Your DNA Reviews

Best Microbiome Test

Looking for the best microbiome kit on the market? Look no further! Our review round-up page has all the information you need to make an informed decision.

Updated on January 31, 2024
Minus IconPlus Icon
12 sources cited
Updated on January 31, 2024
  1. Hemoglobin and Functions of Iron.” University of California San Francisco.
  2. Anemia Due to Excessive Bleeding.” MSD Manual.
  3. Haemoglobin decreases in NSAID users over time: an analysis of two large outcome trials.” Alimentary Pharmacology & Therapeutics.
  4. Autoimmune Hemolytic Anemia.” Cleveland Clinic.
  5. What Is Bone Marrow?” UCSF Benioff Children’s Hospital.
  6. Anemia and infection: a complex relationship.” National Center for Biotechnology Information.
  7. Aplastic Anemia.” National Heart Lung and Blood Institute.
  8. Thalassemia.” National Center for Biotechnology Information.
  9. Iron-Deficiency Anemia.” John Hopkins Medicine.
  10. Vitamin B12 or folate deficiency anaemia.” NHS
  11. Sickle Cell Disease.”
  12. Hemolytic anemia.” Mount Sinai.
Dr. Rizza Mira
Dr. Rizza Mira
Medical Reviewer
Dr. Rizza Mira is a medical doctor and a general practitioner who specializes in pediatrics, nutrition, dietetics, and public health.

As a pediatrician, she is dedicated to the general health and well-being of children and expecting parents. She believes that good nutrition, a healthy lifestyle, and prevention of illness are key to ensuring the health of children and their families.

When she’s not in the hospital, Rizza advocates and mobilizes causes like breastfeeding, vaccination drives, and initiatives to prevent illness in the community.
Cristine Santander
Cristine Santander
Content Contributor
Cristine Santander is a content writer for KnowYourDNA. She has a B.S. in Psychology and enjoys writing about health and wellness.
Back to top icon