The biomedical model uses single factor causes and doesn’t consider all the factors that lead to illness. For example the biomedical model would say smoking is the cause of heart disease, but not all smokers get heart disease so other factors must be involved.
This model also suggests that the body is just a shell for the mind or soul. This is called Cartesian dualism. However the biomedical model doesn’t distinguish between illness and heath and suggests that if you are not ill you are healthy. This doesn’t encourage or promote healthy lifestyles in people.
The biopsychosocial model takes a different approach to health and illness. It is not reductionist and attributes ill health to five factors; ecological systems such as the atmosphere, ecosystems and other life forms that we live with, social systems such as our culture and family, psychological systems, like emotion, behaviour and cognition, biological systems such as our organs tissues and cells, and lastly physical systems such as molecules and atoms. All of these factors can affect us individually, causing illnesses. These factors can be split into two categories; micro levels, which are physically small factors such as hormones, and macro levels, which are more visible factors such as culture. However, the physical size of the micro level factors does not mean it’s effects will be less than the macro level factors.
Taking the example used to illustrate the biomedical model of health, heart disease, may be described by the biopsychosocial model as being caused by; a culture of unhealthy eating or smoking, a family situation where others smoke causing passive smoking, a hereditary disposition to the disease and the patient himself smoking.