Health has a variety of definitions, which have been used for different purposes over time. In general, it refers to physical and emotional well-being, especially that associated with normal functioning of the human body, absent of disease, pain, or injury. Your health is one of the most important things in your life. It affects your physical, mental, and emotional well-being. That's why it's so important to be proactive about your health and take steps to prevent illness and disease. Being proactive in health means taking steps to improve your health before you get sick.