By Renee Yan
Within the body, blood is a living superhighway that delivers life-sustaining components – platelets, antibodies, nutrients, immune cells, and more. Red blood cells, specifically the iron-containing hemoglobin protein that gives blood its red color, have the irreplaceable job of ferrying oxygen to vital organs.
When red blood cells become scarce, this transportation system breaks down, and healthy tissue is starved of oxygen. The result is anemia.
“Technically speaking, we define anemia by the lack of hemoglobin,” said Yu-Min Shen, M.D., Professor of Internal Medicine at UT Southwestern Medical Center and a board-certified hematologist who is a member of the Harold C. Simmons Comprehensive Cancer Center. “There are rare conditions, like thalassemia, where red blood cell counts can be normal while hemoglobin levels are down. But because the two markers generally rise and fall together, we will often explain to patients simply that their red blood cell count is low.”
Many people with anemia might be asymptomatic, but some will experience fatigue, weakness, unusual pallor, dizziness, and even shortness of breath and chest pain if severe enough or if the anemia develops quickly. If left untreated, anemia can lead to complications, such as an irregular heart rate or shortness of breath. In extreme cases, it may lead to organ failure.
Anemia can develop for lots of reasons. Sometimes it’s not a condition by itself. Instead, it’s your body’s way of signaling something else is wrong. It might be poor nutrition, a blood disorder, a genetic disorder, or an underlying chronic illness that interferes with red blood cell production or function.
What are the different types of anemia?
Anemia can develop in the absence of certain vitamins and minerals, including vitamin B12 and folic acid. The most common type is caused by iron deficiency. Iron is essential to the composition of hemoglobin, and your iron levels may be depleted for any number of reasons, Dr. Shen said. These include:
- Blood loss from a wound, ulcer, or heavy menstrual cycle
- Inadequate intake from your diet
- A gastrointestinal disorder that causes absorption issues
Anemia is also a common side effect of bone marrow disease, cancer, chronic inflammation, and kidney disease – all of which impede the development of red blood cells.
“For patients whose anemia is caused by a chronic illness, treatment means addressing the underlying cause,” Dr. Shen explained. “If it’s caused by an inflammatory disorder, we would treat that first, and once we do, we may see an improvement in the red blood cell count and hemoglobin.”
Two other types of anemia are rarer:
- Autoimmune hemolytic anemia occurs when the immune system destroys red blood cells
- Aplastic anemia is a disease of the bone marrow where blood-forming cells are attacked by the immune system and result in a lack of blood cell production
Even certain medications, such as some antibiotics and anti-rejection medications for organ transplant recipients, may lower your red blood cell count by preventing adequate red blood cell production or causing the destruction of red blood cells. There are other conditions or genetic mutations that might affect how oxygen is transported through the body. Some target hemoglobin proteins. Others disrupt the red blood cell’s shape and function – sickle cell disease is one example. Thalassemia, mentioned above, is a problem of not making enough hemoglobin.
In general, women are at greater risk than men, especially those who are pregnant or menstruating, according to the American Society of Hematology. A study by UT Southwestern and Parkland Health found that prenatal iron supplements helped reduce the incidence of anemia and postpartum blood transfusions among underserved pregnant patients. Older adults are also more likely to develop anemia since they often run into more health complications that are known to cause anemia – inadequate nutrition, chronic inflammation, and kidney disease.
Related reading: UT Southwestern study defines anemia in pregnancy using uncomplicated U.S. cases
Team approach for diagnosis and treatment
Screening for anemia and pinning down its exact cause require some investigative work, and its treatment may call for the expertise of multiple physicians. At UT Southwestern, the Blood Disorders Internal Medicine Subspecialties Clinic sees a range of patients, including those with complex cases. Here, classical or benign hematologists work in tandem with other specialists of rare diseases to offer the most accurate diagnosis and effective treatments available.
Tracking down the cause of anemia
The task of uncovering the cause of anemia begins with a complete blood cell count (CBC), a test that assesses the number of blood cells in a sample. It’s often part of a routine lab workup that’s done during an annual visit with a primary care provider.
“It’s usually one of the first tests physicians will order,” Dr. Shen said, “along with a comprehensive metabolic panel, which will give us some basic information about your kidney and liver functions.”
If results return slightly less than what’s considered “normal,” there’s no need for immediate panic. These numbers establish a baseline and are evaluated with other factors, such as your symptoms and their severity. A slight drop in CBC over six months is less concerning than a sharp decline in a shorter period of time – especially when accompanied by symptoms of fatigue or dizziness.
Combing through a person’s medical history may unravel much of the mystery: Does the patient have a history of ulcers or endometriosis? Are they missing iron-rich foods in their diet? Do they have rheumatoid arthritis or another diagnosis of chronic inflammation? These questions help figure out whether the problem lies with the production of blood cells or their loss and destruction.
Tests to help diagnose anemia
Here are a few of the tests your physician might order before making a diagnosis:
- Peripheral blood smear: A blood sample is analyzed under a microscope to count and assess the shape and formation of your blood cells and platelets to check for abnormalities.
- Other blood cell count: Doctors may examine blood samples for developing red blood cells, known as reticulocytes, to assess whether the bone marrow is producing enough.
- Bone marrow aspiration and biopsy: During this outpatient procedure, a physician will extract a sample of your bone marrow to directly analyze the blood forming elements to look for problems.
- Kidney function tests: The kidneys release a hormone called erythropoietin, which stimulates red blood cell production. Chronic kidney disease interferes with this process, so your physician may check certain markers of kidney function, such as blood urea nitrogen, creatinine, and glomerular filtration rate.
- Nutritional markers: A lack of iron, folate, or vitamin B12 may cause anemia.
Questions on blood work results to ask your physician
Understanding your lab results is key to helping you and your medical team decide on a care plan moving forward. Here are a few questions you may consider asking related to your blood work:
- Based on my symptoms and medical history, what is the most likely cause for my anemia?
- Are there additional tests that I need?
- Is my anemia a short-term or long-term condition?
- What is your recommended treatment and what are the possible side effects?
- Do I need regular blood work done to monitor my blood count?
- Should I modify my diet? If so, how?
Diagnosis dictates treatment
Your care plan will depend on the type of anemia you have. If there is an underlying condition, that will often be treated first. Addressing those issues can help alleviate your symptoms. Treatment may include supplements of iron, folic acid, vitamin B12, and erythropoietin, which can be administered through pills, injections, or infusions.
Doctors may also prescribe immunosuppressants for patients whose anemia stems from an autoimmune disorder. In severe cases of aplastic anemia, a bone marrow transplant may help.
“There are also new treatments to try, and drugs are continuously being developed,” Dr. Shen said.
In 2022, for example, the U.S. Food and Drug Administration (FDA) approved a new medication to treat hemolytic anemia caused by a rare genetic disorder called pyruvate kinase deficiency.
In many cases, anemia is actually the result of blood loss. Women who suffer from endometriosis or heavy menstrual periods frequently have anemia. Once doctors trace the bleeding to its source, they can address the cause and return the red blood cell count to a normal range.
Living with anemia
The American Society of Hematology estimates that more than three million people in the U.S. live with anemia. While today’s medical advancements offer several effective treatments, some patients may need to take other steps:
- Follow a nutrient-rich eating plan
- Take medications and supplements as prescribed
- Have their blood cell count checked regularly by their doctor
- Manage any existing chronic conditions that could cause anemia
To discuss anemia treatment and care with a specialist at UT Southwestern, you can make an appointment by calling 214-645-3888 or completing the online form.
