Individual characteristics, including demographic, psychosocial, and structural variables, can affect perceptions (i.e., perceived seriousness, susceptibility, benefits, and barriers) of health-related behaviors. Demographic variables include age, sex, race, ethnicity, and education, among others. Psychosocial variables include personality, social class, and peer and reference group pressure, among others. Structural variables include knowledge about a given disease and prior contact with the disease, among other factors. The health belief model suggests that modifying variables affect health-related behaviors indirectly by affecting perceived seriousness, susceptibility, benefits, and barriers.

Various early information of the Health Belief Model included the concept of cues that can trigger actions. Readiness to action could only be potentiated by other factors particularly by cues to instigate action such as bodily events or by environmental events such as media publicity. For example, women would be more likely to engage in preventive behaviour like going for a pap smear if they are reminded by their family members or heath care providers.  

The integral role of nurses in educating patients regarding preventive healthcare, especially the importance of routine cancer screening was stressed in many studies. Nurses are in a position to influence positive health behaviour, so they should inform patients about the purpose and benefits of regular screening, while assessing the patient's personal risk factors for diseases, and their beliefs and perceptions regarding cancer screening. 

The perceived susceptibility refers to beliefs about the likelihood of getting a disease or condition. Perceived risk of contracting a disease is influenced by an individuals’ subjective perception of their susceptibility to the disease. For example, women who believe there is a high possibility of getting cervical cancer are most likely to be interested in taking the pap smear test. The health belief model predicts that women will be more likely to adhere the cervical cancer screening recommendation if they feel that they are susceptible to cervical cancer. 

Perceived barriers to action refers to the negative aspects of health-oriented actions or which serve as barriers to action and/or that arouse conflicting incentives to avoid action. Perceived barrier refers to the potential negative aspects of particular health action may act as impediments to undertaking recommended behaviours. A kind of subconscious, cost effective analysis occurs wherein individuals weight the expected benefits of behavioural change with perceived barriers such as "could it really help me, but it may be expensive, have negative side effects, and be unpleasant, inconvenient or time consuming". Thus combined with levels of susceptibility and severity provide the motivation to change behaviour and the perception of benefits (minus barrier) provides a preferred course of action.