Access to essential medicines and health products is critical for reaching universal health coverage. Medicines and health products are important for addressing health problems and improve quality of lives. They form an indispensable component of health systems in the prevention, diagnosis and treatment of disease and in alleviating disability and functional deficiency.
Health, as defined by the World Health Organization (WHO), is "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." This definition has been subject to controversy, as it may have limited value for implementation. Health may be defined as the ability to adapt and manage physical, mental and social challenges throughout life.