Why do people get blood disorders? A Comprehensive Guide to Causes

September 27, 2025 •

4 min read

According to the American Society of Hematology, anemia affects more than 3 million people in the U.S., making it one of the most common blood disorders. But beyond statistics, many people wonder, why do people get blood disorders? The reasons are diverse and can be inherited, acquired, or a combination of both.

Quick Summary

Blood disorders can be caused by inherited genetic mutations, deficiencies in key nutrients like iron or vitamin B12, or acquired conditions resulting from infections, autoimmune diseases, or medication side effects.

Key Points

Genetic Factors: Many blood disorders are inherited through faulty genes passed down from parents, such as sickle cell anemia or hemophilia.
Acquired Conditions: Blood disorders can develop later in life due to infections, autoimmune diseases, other illnesses, or exposure to certain medications.
Nutritional Deficiencies: A lack of key nutrients like iron, vitamin B12, or folate is a common cause of acquired anemia.
Bone Marrow Issues: Problems with the bone marrow, where blood cells are produced, are a direct cause of many disorders, including aplastic anemia and leukemia.
Environmental Exposure: Contact with certain toxins, chemicals, or radiation can trigger the development of blood disorders over time.
Accurate Diagnosis is Key: Distinguishing between inherited and acquired causes through tests like a CBC, bone marrow biopsy, and genetic testing is crucial for proper treatment.

The Fundamental Causes: Inherited vs. Acquired

Blood disorders are conditions that affect one or more components of the blood, including red blood cells, white blood cells, and platelets. The root causes of these conditions can typically be categorized into two primary groups: inherited and acquired.

Inherited Blood Disorders: When Genes Play a Role

Many blood disorders are the result of faulty genes inherited from one's parents. These genetic mutations can affect how the body produces blood cells or proteins, leading to a lifelong condition.

Examples of inherited blood disorders include:

Sickle Cell Disease: Caused by a genetic mutation that leads to the production of abnormal hemoglobin. This forces red blood cells into a sickle or crescent shape, which can block blood flow and cause pain and other complications.
Thalassemia: Another inherited blood disorder that affects hemoglobin production. It can result in severe anemia.
Hemophilia: This well-known genetic bleeding disorder is caused by a lack of or defect in specific clotting proteins (factors).
Von Willebrand Disease: The most common inherited bleeding disorder, caused by a defect or deficiency in the von Willebrand clotting factor.
Hereditary Spherocytosis: A genetic condition where a defect in the red blood cell membrane causes the cells to be sphere-shaped instead of disc-shaped, leading to their premature destruction.

Acquired Blood Disorders: Developing Over Time

Unlike inherited disorders, acquired blood disorders are not present at birth. They develop during a person's lifetime due to a variety of factors.

Common causes of acquired blood disorders:

Infections: Certain viruses and bacteria can trigger blood disorders. For example, some viral infections can cause temporary low white blood cell counts.
Autoimmune Diseases: Conditions where the body's immune system mistakenly attacks its own healthy cells can lead to blood disorders. Pernicious anemia, where the body attacks cells needed to absorb vitamin B12, is a prime example.
Nutritional Deficiencies: A lack of essential vitamins and minerals can severely impact blood health. Iron-deficiency anemia is a very common example, often caused by poor diet or blood loss. Vitamin B12 and folate deficiencies can also lead to anemia.
Medications and Treatments: Certain drugs, including chemotherapy and some antibiotics, can affect bone marrow function and blood cell production.
Underlying Medical Conditions: Diseases such as kidney failure, liver disease, or chronic inflammatory conditions can disrupt the body's blood-producing processes.
Environmental Factors: Exposure to toxins and certain chemicals can trigger blood disorders. For instance, some industrial chemicals or radiation exposure can lead to aplastic anemia.

The Role of Bone Marrow

The bone marrow is the soft, spongy tissue inside bones where blood cells are produced. Many blood disorders are directly linked to problems with the bone marrow.

A problem with the bone marrow can lead to:

Aplastic Anemia: The bone marrow stops producing new blood cells, leading to severe anemia.
Myelodysplastic Syndromes (MDS): The bone marrow produces poorly formed or non-functional blood cells.
Blood Cancers: Leukemia and other blood cancers, like myeloma, are caused by abnormal cell production within the bone marrow.

Inherited vs. Acquired Blood Disorders

Understanding the distinction between inherited and acquired causes is critical for proper diagnosis and treatment. This comparison table highlights the key differences.


Feature	Inherited Blood Disorders	Acquired Blood Disorders
Onset	Usually present at birth, though symptoms may appear later in life.	Develops later in life due to external factors or illness.
Cause	Genetic mutations passed down from parents.	Environmental factors, infections, autoimmune issues, or other diseases.
Risk Factors	Family history of the specific disorder.	Exposure to toxins, certain medications, nutritional status, and existing health conditions.
Prevention	Not preventable, but genetic counseling can help assess risk.	Some types are preventable, such as those caused by nutritional deficiencies.
Lifespan	Often lifelong, chronic conditions.	Can be acute (temporary) or chronic depending on the cause.

How Diagnostic Procedures Uncover the Cause

When a blood disorder is suspected, a hematologist will perform a series of diagnostic tests to determine the specific cause and type. This process often involves several steps:

Blood Tests: A complete blood count (CBC) measures the number of red blood cells, white blood cells, and platelets. Further blood work can check for vitamin and mineral levels, abnormal proteins, and signs of infection.
Physical Examination: Checking for signs like easy bruising, fatigue, enlarged spleen, or swollen lymph nodes.
Bone Marrow Biopsy: A small sample of bone marrow is extracted and examined to assess blood cell production. This is particularly useful for identifying myelodysplastic syndromes and blood cancers.
Genetic Testing: If an inherited disorder is suspected, genetic testing can confirm the presence of specific gene mutations.

Conclusion: Taking Control of Your Health

The reasons why do people get blood disorders are varied and complex, ranging from genetic predispositions to environmental triggers. While some conditions are beyond our control, understanding the causes is the first step toward effective management and treatment. For comprehensive information on specific blood disorders and their management, visiting reputable medical resources like the American Society of Hematology is highly recommended.

For those with acquired conditions related to nutrition, simple lifestyle changes and dietary adjustments can make a significant difference. For those with inherited disorders, advances in medicine offer more effective treatments than ever before. Always consult a healthcare professional for a personalized diagnosis and treatment plan. Empowering yourself with knowledge is key to navigating the challenges of any blood disorder.

Frequently Asked Questions

No, not all blood disorders are inherited. While some, like hemophilia and sickle cell disease, are genetic, many others are acquired. Acquired blood disorders develop over a person's lifetime due to factors like infections, nutritional deficiencies, or autoimmune conditions.

Yes, a poor diet can cause certain types of blood disorders, most notably nutritional anemias. A lack of essential vitamins and minerals, such as iron, vitamin B12, and folate, can disrupt the production of healthy blood cells.

The bone marrow is the primary site of blood cell production. Problems with the bone marrow can directly cause blood disorders, whether it's not producing enough cells (as in aplastic anemia) or producing abnormal, cancerous cells (as in leukemia).

Yes, autoimmune diseases can cause blood disorders. In these conditions, the body's immune system mistakenly attacks its own blood cells or components necessary for blood health, leading to issues like autoimmune hemolytic anemia or pernicious anemia.

Yes, some medications can cause blood disorders as a side effect. Chemotherapy is a well-known example that can suppress bone marrow function, but other drugs can also impact blood cell production or function.

Blood disorders are diagnosed through a combination of methods, including a complete blood count (CBC), physical examination, and further tests as needed. These may include a bone marrow biopsy, genetic testing, or specific checks for vitamin levels.

The preventability of blood disorders depends on the cause. Inherited disorders are not preventable, though genetic counseling can help families. Acquired disorders may be preventable or manageable by addressing underlying health conditions, ensuring proper nutrition, and limiting exposure to environmental toxins.