Introduction: The global prevalence of anemia affects approximately 33% of the global population, equivalent to more than 2 billion people, and is more common in women and children. Some developing countries, particularly in Africa and South America, have higher rates, with certain countries, such as Nigeria, India, and Bangladesh, reporting prevalence exceeding 50% in certain groups.

According to data from the World Health Organization and recent studies, anemia is a significant cause of hospitalizations in low- and middle-income countries; however, there is no exact, unified global percentage due to differences in health systems and epidemiological records. However, anemia is recognized as a factor that increases morbidity and mortality and the length of hospital stays. The vast majority of patients admitted to hospitals have medically significant comorbidities.

Method: This is an observational retrospective cross-sectional study using routinely collected hospital discharge data (2019–2025) from a high-specialty University hospital in Mexico.

Results: The discharges of 5,332 patients were studied, of whom 4,541 were first-admitted and 791 were readmissions. 79.59% of the anemias were secondary and 20.40% primary. The patient population consisted of 53.03% females and 46.96% males. The predominant age group was 51-60 years. Length of hospital stay ranged from less than 3 days to more than 11 days.

Unspecified anemia, Other specified anemias, Aplastic anemia, Iron deficiency anemia, Anemia in other chronic diseases, Acute posthemorrhagic anemia, Other iron deficiency anemias, Unspecified nutritional anemia, Other anemias, Anemia in neoplastic disease, and Anemia in Chronic Disease were the main ones.

Discussion and Conclusion: Several authors have found data similar to ours: Migone's study found nutritional deficiency, chronic kidney disease, and anemia of chronic disease in 36%, 15%, and 25% of cases, respectively. Anemia is a frequent cause of hospital admissions in highly specialized facilities. However, the trend in recent years has been downward.