Personal health beliefs usually affect health behavior. Effects of health behavior can be both positive and negative. Positive health behaviors include immunizations, proper sleep patterns, adequate exercise and nutrition. Negative health behaviors include smoking, drugs or alcohol abuse, poor diet and refusal to take necessary medication. A risk factor is any physical, environmental, psychological condition or health behavior that increases the vulnerability of an individual to illness or accident.
Risk factors can include variables other than physical conditions, such as emotional stressors.
The presence of risk factors does not mean that a disease will develop but their presence can increase the chances that the individual will experience a particular disease. Risk factors play a role in how an individual's health status is determined. Knowledge of risk factors can lead to identification of health promotion and illness prevention activities which, in turn, will lead to modification of the risk factors. Risk factors include the following interrelated categories - genetic, physiological, age, physical environment and lifestyle. While it provides individual data, it is not a comprehensive diagnostic instrument for individual health problems.