Some types of anemia run in families, but not all

Whether anemia is hereditary depends on which type you have. Some forms of anemia are passed down through genes from parents to children. Others develop because of diet, illness, or blood loss — things that happen to you during your life, not things you were born with. A few types can be either hereditary or acquired, depending on the cause.

If you or a family member has been diagnosed with anemia, knowing whether it runs in families matters because it changes what doctors look for and how they monitor your health. It also affects whether your siblings or children might develop it.

Key Takeaways

  • Hereditary anemias include sickle cell disease, thalassemia, and hereditary spherocytosis — all caused by genes passed from parents to children.
  • Acquired anemias result from iron deficiency, vitamin B12 deficiency, chronic disease, or blood loss, and do not run in families.
  • Some people inherit a gene that makes them a carrier but does not cause anemia itself, though they can pass the gene to their children.
  • A genetic counselor or hematologist can review your family history and test results to determine whether your anemia is hereditary.
  • If you have a hereditary form, your blood relatives may want to know their own status, especially before having children.

The hereditary forms: sickle cell, thalassemia, and others

Sickle cell disease is the most common hereditary anemia in the United States. It happens when a person inherits a specific gene change from both parents. The red blood cells become crescent-shaped instead of round, which causes them to get stuck in blood vessels and break down faster than normal cells. This leads to pain, organ damage, and chronic anemia.

Thalassemia is another hereditary form. It affects how the body makes hemoglobin, the protein inside red blood cells that carries oxygen. People with thalassemia inherit faulty genes from both parents, and their red blood cells do not work properly. The severity ranges from mild to life-threatening, depending on which genes are inherited.

Hereditary spherocytosis is a less common hereditary anemia where red blood cells are shaped like spheres instead of discs. They break down faster than normal, causing anemia. A person usually needs to inherit the gene from only one parent for this form to develop.

Other hereditary anemias include pyruvate kinase deficiency and glucose-6-phosphate dehydrogenase (G6PD) deficiency. These are rarer but follow the same pattern: a gene change inherited from parents causes the red blood cells to malfunction.

The acquired forms: not inherited, but common

Iron deficiency anemia is the most common type of anemia worldwide. It develops when the body does not have enough iron to make hemoglobin. This can happen because of poor diet, heavy menstrual bleeding, pregnancy, digestive problems that prevent iron absorption, or chronic blood loss. None of these causes are hereditary — they are circumstances that occur during a person's life.

Vitamin B12 deficiency anemia happens when the body cannot absorb or obtain enough B12. Some people lack the protein needed to absorb B12 from food, which can run in families, but the anemia itself is not inherited — it develops only if the person does not get enough B12. Others develop B12 deficiency because of digestive surgery, certain medications, or a strict vegan diet.

Anemia of chronic disease occurs when a long-term illness like kidney disease, cancer, rheumatoid arthritis, or heart failure interferes with red blood cell production. The underlying illness may or may not be hereditary, but the anemia itself is a consequence of that illness, not a separate inherited condition.

Hemolytic anemia — where red blood cells break down too quickly — can be hereditary or acquired. Acquired causes include autoimmune disease, infections, or certain medications. A doctor must determine the cause to know whether it runs in families.

Carriers: inheriting the gene without the disease

For some hereditary anemias, a person can inherit one copy of a faulty gene from one parent and remain healthy. This person is called a carrier. They do not have anemia, but they carry the gene and can pass it to their children.

For example, sickle cell trait is the carrier state for sickle cell disease. A person with sickle cell trait has one normal gene and one sickle cell gene. They usually have no symptoms, but if they have a child with someone else who carries the gene, that child could inherit two copies and develop sickle cell disease.

The same applies to thalassemia. A person who carries one thalassemia gene is usually healthy but can pass the gene to their children. If both parents are carriers, each child has a 25 percent chance of inheriting two copies and developing thalassemia.

Carriers often do not know they carry a gene until they have genetic testing or until a child is diagnosed. If you have a family history of hereditary anemia, genetic testing can tell you whether you are a carrier, which matters if you are planning to have children.

How doctors determine whether anemia is hereditary

The first step is a detailed family history. A doctor will ask whether anyone in your family — parents, siblings, grandparents, aunts, uncles, or cousins — has had anemia, sickle cell disease, thalassemia, or related conditions. They will also ask about the age when relatives were diagnosed and how severe their anemia was.

Blood tests come next. A complete blood count (CBC) measures red blood cell count, hemoglobin level, and cell shape. A peripheral blood smear lets a technician look at red blood cells under a microscope to see if they are shaped abnormally. These tests can suggest a hereditary form.

If hereditary anemia is suspected, a doctor may order genetic testing. This involves a blood sample sent to a laboratory to look for specific gene changes. Genetic testing can confirm a diagnosis, identify whether you are a carrier, and sometimes predict how severe the anemia will be.

A hematologist — a doctor who specializes in blood disorders — often coordinates this workup. If genetic testing is needed, a genetic counselor can explain what the results mean and discuss the implications for your family.

What to tell your family members

If you are diagnosed with hereditary anemia, your blood relatives may want to know whether they are affected or are carriers. This is especially important for siblings and for anyone planning to have children.

For sickle cell disease and thalassemia, both parents of an affected person are carriers. If you have one of these conditions, your parents definitely carry the gene, and your siblings have a chance of being affected or being carriers. Genetic testing can tell each person their status.

If you are a carrier of a hereditary anemia gene, your children have a 50 percent chance of inheriting that gene from you. If your partner is also a carrier or affected, the risk to your children is higher. Knowing this before having children gives you and your partner time to discuss options and plan for care if needed.

Some families choose to share genetic test results with relatives so they can decide whether to be tested. Others prefer to keep the information private. There is no single right approach — it depends on your family's values and communication style.

Frequently Asked Questions

If my parent has anemia, will I definitely inherit it?

Not necessarily. It depends on the type. If your parent has hereditary anemia like sickle cell disease or thalassemia, you have a chance of inheriting it — usually 25 to 50 percent, depending on whether your other parent is a carrier. If your parent has acquired anemia from iron deficiency or B12 deficiency, you will not inherit the anemia itself, though you might inherit a tendency toward the same deficiency if it is diet-related.

Can I have hereditary anemia if no one in my family has it?

Yes, but it is less common. Hereditary anemias can appear in a family for the first time if both parents happen to carry the same recessive gene without knowing it. Genetic testing can confirm whether your anemia is hereditary even if no family member has been diagnosed.

What does it mean if I am a carrier?

A carrier has one copy of a faulty gene but usually has no symptoms and normal blood counts. You cannot develop the disease yourself, but you can pass the gene to your children. If your partner is also a carrier or affected, your children face a higher risk of inheriting the condition.

Should I have genetic testing if anemia runs in my family?

Genetic testing can tell you whether you are affected, a carrier, or unaffected. It is most useful if you are planning to have children, if you have symptoms of anemia, or if you want to know your status for your own health planning. A doctor or genetic counselor can help you decide whether testing makes sense for your situation.

Can lifestyle changes prevent hereditary anemia?

No. Hereditary anemias are caused by gene changes present from birth, so diet, exercise, or other lifestyle changes cannot prevent them. However, good nutrition and medical care can help manage symptoms and prevent complications. For acquired anemias like iron deficiency, lifestyle changes and treatment can resolve the anemia.