Health literacy is the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions.1
Health literacy is dependent on individual and systemic factors:
Communication skills of lay persons and professionals
Lay and professional knowledge of health topics
Culture
Demands of the healthcare and public health systems
Demands of the situation/context
Health literacy affects people's ability to:
Navigate the healthcare system, including filling out complex forms and locating providers and services
Share personal information, such as health history, with providers
Engage in self-care and chronic-disease management
Understand mathematical concepts such as probability and risk
Health literacy includes numeracy skills. For example, calculating cholesterol and blood sugar levels, measuring medications, and understanding nutrition labels all require math skills. Choosing between health plans or comparing prescription drug coverage requires calculating premiums, copays, and deductibles.
In addition to basic literacy skills, health literacy requires knowledge of health topics. People with limited health literacy often lack knowledge or have misinformation about the body as well as the nature and causes of disease. Without this knowledge, they may not understand the relationship between lifestyle factors such as diet and exercise and various health outcomes.
Health information can overwhelm even persons with advanced literacy skills. Medical science progresses rapidly. What people may have learned about health or biology during their school years often becomes outdated or forgotten, or it is incomplete. Moreover, health information provided in a stressful or unfamiliar situation is unlikely to be retained.
Reference
1. U.S. Department of Health and Human Services. 2000. Healthy People 2010. Washington, DC: U.S. Government Printing Office. Originally developed for Ratzan SC, Parker RM. 2000. Introduction. In National Library of Medicine Current Bibliographies in Medicine: Health Literacy. Selden CR, Zorn M, Ratzan SC, Parker RM, Editors. NLM Pub. No. CBM 2000-1. Bethesda, MD: National Institutes of Health, U.S. Department of Health and Human Services.
Only 12 percent of adults have Proficient health literacy, according to the National Assessment of Adult Literacy. In other words, nearly nine out of ten adults may lack the skills needed to manage their health and prevent disease. Fourteen percent of adults (30 million people) have Below Basic health literacy. These adults were more likely to report their health as poor (42 percent) and are more likely to lack health insurance (28 percent) than adults with Proficient health literacy. 1
Low literacy has been linked to poor health outcomes such as higher rates of hospitalization and less frequent use of preventive services (see Fact Sheet: Health Literacy and Health Outcomes). Both of these outcomes are associated with higher healthcare costs.
1. Kirsch IS, Jungeblut A, Jenkins L, Kolstad A. 1993. Adult Literacy in America: A First Look at the Results of the National Adult Literacy Survey (NALS). Washington, DC: National Center for Education Statistics, U.S. Department of Education.