Health literacy refers to an individual's ability to understand healthcare information to make appropriate decisions. Healthcare professionals are obligated to make sure that patients understand information to maximize the benefits of healthcare. The National Assessment of Adult Literacy (NAAL) provides information on the literacy/health literacy levels of the U.S. adult population. The NAAL is the only large-scale survey of health literacy. The results of the NAAL provide information on literacy/health literacy and the relationship between background variables and literacy/health literacy. Multiple variables with potential for a relationship with literacy/health literacy were chosen for the NAAL including, but not limited to, education, language, race, gender, income, overall health, seeking health information, and health insurance.