This report analyzes sex-based trends in Hemoglobin (g/dL) using 82,926 complete records from NHANES survey cycles spanning 1999 to 2018. The analysis reveals consistent differences between males and females and highlights subtle time-related patterns in population hemoglobin levels. Data were sourced from the publicly available NHANES database provided by the U.S. Centers for Disease Control and Prevention (CDC).

This reproducible R script automates the download, labeling, and merging of NHANES Complete Blood Count (CBC) and Demographic datasets across 10 survey cycles (1999–2018). Ideal for researchers conducting longitudinal biomarker surveillance and population health analysis, the pipeline uses httr, haven, dplyr, and rvest to create a unified, analysis-ready dataset.