Purpose: The purpose of this paper is to review evidence related to the factors that influence people's understanding of health information and how miscommunication of health information can jeopardize people's health. Design/methodology/approach: A literature review was conducted of English language articles, cited in major literature databases from the last 40 years, which describe factors related to comprehension of health information. A total of 93 articles were included. Findings: The paper finds that health communication should take into consideration the role of the following factors on the processing and interpretation of health information health literacy, format presentation of information, and human cognitive biases and affective/personal influences. Practical implications: Health communication is a major component of health care. Every health care encounter involves exchange of information, which is intended to enhance people's knowledge in order to assist them to make an informed decision about their health care. However, the mere act of providing information does not guarantee comprehension. People's comprehension of information depends on several factors, including health literacy and numeracy skills, the format presentation of health information and human cognitive biases in the information processing and interpretation. Ineffective health communication can result in a wide range of direct and indirect health consequences including failure to understand and comply with treatment, poorer health status, increased risk of injuries, increased hospitalization, and decreased use of preventive services. Originality/value: This paper provides health professionals and educators with an overview of important issues related to health communication and highlights strategies that facilitate effective communication to help people to make informed decisions about their health care.