2.7: Models of Health Promotion and Illness Prevention II

The person's health status fluctuates continually, varying from being in good health to becoming ill and returning to being healthy. To understand the concept of illness prevention, there are two models. First, the health-illness continuum model is a graphic representation of an individual's wellness. It states that a person is considered healthy in the absence of physical disease and the presence of good emotional health.

The agent-host-environment model states that disease results from interacting with the agent and the susceptible host in an environment. In this triad model, the agent is what causes the disease, the host is an organism, usually a human or an animal, that harbors the disease, and the environment is the surrounding area that causes or allows disease transmission. To successfully adapt to a chronic illness, the person must learn to live as normally as possible and maintain a positive self-concept and sense of hope. The person must also recognize what they can control and what they cannot control in their own life.

Throughout life, an individual's state of health continually changes between wellness and illness. Illness prevention is the term used for a range of approaches to reduce the risk of ill health and promote good health.

The health-illness continuum model can be visually represented with a two-way arrow showing health and illness on each side.

Movement towards the right symbolizes achieving a higher level of health, which may be facilitated by health awareness, education, and growth.

In contrast, movement towards the left symbolizes a decline in an individual's health, which can progress from early signs of potential illness, to symptoms, then disability, and, ultimately, premature death.    

In the agent-host-environment model, disease results from the interaction between an agent and a susceptible host in an environment.

In this triad, the agent is the cause of disease. The host is an organism, usually a human or an animal, that harbors the disease, and the environment is the surrounding that causes or allows disease transmission.

In this model, health is maintained when there is a balance between the three components.