Red blood cell disorders refer to conditions that affect either the number or function of red blood cells (RBCs). Also known as erythrocytes, RBCs are concave, disc-shaped cells that move through blood vessels, carrying oxygen throughout the body.

RBCs are one of the main components of blood. They are among the most abundant types of cells. The human body produces roughly 2 million RBCs every second, and they are the reason for the distinctive red color of blood. They have the important role of carrying oxygen from the lungs to the rest of the body and returning carbon dioxide for the lungs to exhale.

There are many different types of RBC disorders, including conditions that affect the production, components, and abilities of RBCs. Dysfunction of RBCs can lead to several issues in the body.

While symptoms can vary depending on the disorder, many conditions share similar ones. Identifying and treating RBC disorders as quickly as possible may help to alleviate or manage symptoms and reduce the risk of potential complications.

In this article, we will discuss some of the common RBC disorders.

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RBC disorders are conditions that affect RBCs, which are responsible for carrying oxygen from the lungs to the rest of the body. There are many types of RBC disorders, which health experts can categorize by the kind of structure they affect. Some examples include:


Hemoglobinopathies are disorders that involve the hemoglobin protein within RBCs. Hemoglobin is an iron-rich molecule responsible for the red color of the cells. Hemoglobinopathies cause an abnormal production or change the structure of the hemoglobin. Examples of hemoglobinopathies include:

  • sickle cell anemia
  • thalassemia
  • hemoglobin C disease
  • hemoglobin S-C disease

Cytoskeletal abnormalities

Cytoskeletal abnormalities in RBCs include conditions that change the structure or permeability of the RBC or its membranes. Health experts may also refer to these conditions as RBC membranopathies. Examples of cytoskeletal abnormalities include hereditary spherocytosis and elliptocytosis.


RBC enzymopathies are genetic conditions that affect the production of enzymes in RBCs and cell metabolism. Examples of RBC disorders that involve enzyme deficiencies include glucose-6-phosphate dehydrogenase deficiency and pyruvate kinase deficiency.

Symptoms of RBC disorders can vary depending on their type, severity, and how they affect the cells. However, as these disorders affect the functioning of RBCs, some symptoms may overlap. Symptoms that may occur with various RBC disorders include:

  • weakness
  • fatigue
  • shortness of breath
  • feeling faint when standing up too quickly
  • rapid heartbeat
  • trouble focusing
  • tingling or numbness in the hands or feet
  • jaundice or yellowing of the skin

Anemia occurs when a person has a low number of healthy RBCs. This may happen due to changes in the cell itself or components of the cell, such as hemoglobin. There are different types of anemia, each with its own causes.

Iron deficiency anemia

A low dietary intake of iron or blood loss due to issues such as very heavy menstruation may cause iron deficiency anemia. More serious causes include blood loss from internal bleeding in the gastrointestinal tract or cancers.

Pernicious anemia

Pernicious anemia is a rare disorder in which the body has trouble using vitamin B-12, a key component in making RBCs. This may happen due to an autoimmune condition or other cause weakening the stomach lining, which makes cells that bind to vitamin B-12 so the intestines can digest them.

Aplastic anemia

Aplastic anemia occurs when the body stops producing enough new blood cells. This can happen when there is damage in the bone marrow, which creates blood cells. Aplastic anemia can be present at birth or may occur after damage to the marrow from exposure to treatments such as chemotherapy, radiation, or other toxic chemicals.

Sickle cell anemia

Sickle cell anemia is a type of sickle cell disease. Sickle cell disease creates blood cells that are misshapen and die too early. This causes a shortage of RBCs and may lead to other issues such as the cells having difficulty traveling through the blood vessels.

Sickle cell disease is an inherited condition. There are a few different types of sickle cell disease, depending on the traits a person inherits from their parents. Sickle cell anemia, also called HbSS, is a more severe form of sickle cell disease.

Autoimmune hemolytic anemia

Autoimmune hemolytic anemia (AHA) refers to a group of autoimmune disorders where the immune system mistakenly attacks and destroys its own RBCs, leading to the body not having enough.

Some cases of AHA have no known cause. Some cases may occur with other illnesses affecting the immune system, such as leukemia, lupus, or mononucleosis. It is possible to acquire AHA after taking some medications, such as penicillin.


Spherocytosis is a condition that causes the body to produce abnormal RBCs that are rounder and more spherical than the healthy disc shape of a normal RBC. This makes the blood cells more fragile and prone to breaking.

Spherocytosis is a type of hemolytic anemia. It is hereditary, passed from a person to their child through genetic mutations.

Hereditary nonspherocytic hemolytic anemia (HNHA)

HNHA refers to an inherited type of anemia that causes RBCs to break sooner than normal healthy blood cells do. There are a number of different inherited mutations that may cause changes in the genes that lead to the condition.

Thalassemia is a condition that affects the body’s ability to produce hemoglobin and RBCs. As a result, this typically causes a person to have fewer healthy RBCs. Thalassemia is an inherited condition passed through the genes. There are a few types of thalassemia, depending on which traits the parents pass to their children.

Polycythemia, or erythrocytosis, is a condition in which the body has an increased number of RBCs. The extra blood cells can make the blood thicker and lead to difficulties with blood flow, which can increase the risk of other health issues.

Polycythemia may be primary or secondary. Primary polycythemia, called polycythemia vera, is a slow-growing type of blood cancer. It will typically also cause an increase in white blood cells and platelets. Secondary polycythemia, or erythrocytosis, can result from factors such as:

  • smoking
  • steroid use
  • chronic oxygen deficiency in the arteries
  • some types of tumors

Malaria is a condition that occurs from a parasite that infects some types of mosquitos. Malaria may lead to severe sickness, including anemia, as the parasite infects and destroys RBCs.

Infected mosquitos can pass the parasite into humans. It may also pass through other sources of shared blood, such as blood transfusions, shared needles, or from a mother to infant during delivery.

Red blood cell disorders are conditions that affect the functioning of RBCs, which play an important role in transporting oxygen around the body. As these disorders affect RBCs, they may share some similar symptoms, such as weakness, fatigue, and shortness of breath.

There are many different types and causes of RBC disorders. A healthcare professional may refer people to experts in diagnosing and treating blood disorders, known as hematologists.