The three levels of prevention are primary, secondary and tertiary. In primary prevention, a disorder is prevented from developing. Vaccines, counseling to change high-risk behaviors, and sometimes chemoprevention are types of primary prevention. Primary prevention denotes an action taken to prevent the development of a disease in a person who is well and does not (yet) have the disease in question.
You don't prevent rashes or treat them right away, but you're softening their impact by helping people live with their eruptions as well as possible. Prevention includes a wide range of activities known as “interventions aimed at reducing risks or threats to health”. To prevent recurrence, it is important to understand the risk factors, but the risk factors for a primary episode may be different from those of a repeated episode, so the risk factors of concern in this case are not those of a first stroke (C), which has already occurred, but those of a second stroke cerebrovascular. Tertiary prevention seeks to reduce the impact of established illness by eliminating or reducing disability, minimizing suffering and maximizing potential years of quality of life.
For many health problems, a combination of primary, secondary and tertiary interventions is needed to achieve a significant degree of prevention and protection. The goal of primary prevention is to take steps to prevent the development of an illness or injury in a person who is “okay”. The goal of each level of prevention is to prevent the onset of a disease or to identify the disease early in order to treat and resolve it. Screening for carotid stenosis (E) is, by definition, secondary prevention (screening for asymptomatic disease).
The primary prevention approach focuses on preventing the disease before it develops; secondary prevention attempts to detect a disease early and intervene early; and tertiary prevention aims to control the established disease in a person and avoid further complications. If you approach the upstream company that is dumping the chemical into the river and causes it to stop, you are participating in primary prevention. Tertiary prevention involves ongoing medical care as a way to relieve symptoms of a negative health condition. For example, dietary measures used to prevent the progression of coronary artery disease after a heart attack (E) could serve as primary prevention for the development of diabetes in the same person.
Primary prevention has the potential to reach large portions of the population and, therefore, can have a substantial impact on the health of the population while remaining cost-effective. However, as this example shows, prevention experts say that the more “upstream” one of the negative health outcomes is, the more likely it is that any intervention will be effective. Post-exposure prophylaxis (C) for rabies is a secondary prevention, which prevents the possible disease contracted from manifesting.