Why is anemia common in the elderly?

Oct 20, 2025 2 min read •

senior care Healthy Aging

According to the American Society of Hematology, approximately 10 percent of Americans over age 65 are anemic. This prevalence increases significantly with age and comorbid conditions, prompting many to ask, "why is anemia common in the elderly?"

Quick Summary

Anemia is prevalent in older adults due to a complex interplay of factors, including chronic inflammation from age-related diseases, nutritional deficiencies, and reduced kidney function, rather than being a normal sign of aging. Underlying conditions, GI bleeding, and certain medications further contribute to the higher risk and challenge diagnosis.

Key Points

Not a Normal Part of Aging: While common, anemia in seniors is a medical condition with treatable underlying causes, not an inevitable consequence of getting older [1].
Chronic Illness is a Primary Driver: Many age-related conditions, like kidney disease and autoimmune disorders, cause inflammation that disrupts red blood cell production [1].
Nutrient Deficiencies Play a Major Role: Inadequate iron, vitamin B12, and folate intake or malabsorption are frequent culprits, often linked to GI issues [1, 3].
Medications Can Contribute: Polypharmacy, the use of multiple drugs, can cause bleeding or interfere with blood cell production [1].
Diagnosis Can Be Complex: Anemia in the elderly is often multifactorial, sometimes requiring extensive investigation to identify the specific causes and tailor treatment [1].

The Multifactorial Causes of Anemia in Older Adults

Anemia is a medical condition defined by a deficiency of healthy red blood cells or hemoglobin. While often misattributed to simple aging, its high prevalence in older adults is due to several interrelated causes [1]. Understanding these factors is the first step toward effective management and improved quality of life for seniors.

Chronic Inflammation and Disease

Anemia of chronic disease (ACD), also called anemia of inflammation (ACI), is a leading cause of anemia in the elderly, driven by inflammatory cytokines more prevalent with age and chronic illnesses like autoimmune diseases, infections, cancer, and heart failure [1, 2]. Inflammation disrupts iron regulation, leading to a functional iron deficiency where iron is stored but not available for red blood cell production [1].

Nutritional Deficiencies and Malabsorption

Older adults are prone to deficiencies in nutrients essential for red blood cell production, particularly vitamin B12 and folate [1]. Reduced stomach acid, chronic atrophic gastritis, and poor diet can impair B12 absorption [1, 3]. Iron deficiency, often due to chronic blood loss from conditions like ulcers or diverticulosis, also contributes [1, 3]. Deficiencies in copper, zinc, and selenium can also play a role [1].

Chronic Kidney Disease (CKD)

Declining kidney function with age is a significant cause of anemia [1]. Healthy kidneys produce erythropoietin (EPO), a hormone stimulating red blood cell production [1]. Reduced kidney function means less EPO, leading to fewer red blood cells [1].

Medication-Induced Anemia and Blood Loss

Polypharmacy is common in seniors and increases anemia risk [1]. Medications like NSAIDs and blood thinners can cause GI bleeding [1]. Chemotherapy can suppress bone marrow function, and other drugs like ACE inhibitors and anticonvulsants have been linked to anemia [1]. Repeated blood draws can also contribute [1].

Unexplained Anemia of Aging (UAA) and Other Hematologic Issues

About one-third of anemia cases in older adults are unexplained (UAA) [1]. Potential age-related changes include decreased bone marrow reserve, hormonal shifts, and clonal hematopoiesis, which can lead to less effective blood cell production [1].

Comparison of Major Anemia Types in Seniors


Feature	Iron-Deficiency Anemia (IDA)	Anemia of Chronic Disease (ACD)	Vitamin B12 Deficiency
Cause	Blood loss (often GI), poor intake, malabsorption	Chronic inflammation (cancer, autoimmune disease)	Decreased B12 absorption, poor intake
Common Lab Finding	Low serum iron, low ferritin, high TIBC	Low serum iron, normal or high ferritin	Low serum B12
Typical Red Cell Size	Microcytic (small)	Normocytic (normal)	Macrocytic (large)
Treatment	Iron supplements (oral or IV), address blood loss	Treat underlying chronic disease; iron not always effective	B12 supplements or injections

Conclusion

Anemia in the elderly is a complex issue driven by multiple factors, including nutritional deficiencies, chronic inflammation, kidney decline, medication use, and unexplained age-related changes [1]. Medical evaluation is crucial to identify the underlying cause(s) [1]. Effective management can significantly improve symptoms and quality of life [1]. Taking a proactive approach can help address this common but treatable condition [1]. For a comprehensive overview of aging and health, consult the National Institute on Aging website.

Frequently Asked Questions

Early signs can be subtle and often mistaken for normal aging, including fatigue, weakness, dizziness, and pale skin. More severe symptoms may involve shortness of breath or a rapid heart rate [1].

Diagnosis typically begins with a complete blood count (CBC) test, which measures hemoglobin levels and red blood cell counts. Further tests may be needed to identify the underlying cause, such as checking for iron, B12, or folate deficiencies [1, 3].

Yes, a nutrient-rich diet is crucial [1]. For iron-deficiency anemia, iron-rich foods are important [1]. For vitamin B12 deficiency, fortified cereals or supplements may be needed, as malabsorption is common [1, 3].

In iron-deficiency anemia, the body lacks enough iron [1]. In anemia of chronic disease, inflammation prevents the proper use of iron for red blood cell production [1]. Testing helps differentiate the two [1, 3].

No, anemia is not always caused by nutritional deficiencies. While nutrient deficits are common causes, anemia in seniors can also result from chronic inflammation, chronic kidney disease, medications, and underlying bone marrow conditions [1].

The kidneys produce a hormone called erythropoietin (EPO), which stimulates red blood cell production [1]. As kidney function declines with age, so does EPO production, leading to anemia [1].

Yes, seniors are at a higher risk for anemia caused by chronic blood loss from the gastrointestinal tract due to conditions like ulcers [1]. This risk is often compounded by the use of blood-thinning medications [1].

Yes, certain medications frequently used by seniors, such as NSAIDs and blood thinners, can contribute to or cause anemia through mechanisms like chronic bleeding or bone marrow suppression [1].

Yes, a significant portion of anemia in older adults is classified as 'unexplained anemia of aging' (UAA), often attributed to subtle age-related changes in bone marrow function and hormonal levels [1].

References

Medical Disclaimer

This content is for informational purposes only and should not replace professional medical advice. Always consult a qualified healthcare provider regarding personal health decisions.