Levels of Prevention: Primordial, Primary, Secondary, Tertiary and Quaternary
In short: Prevention works at five levels: stopping risk factors from emerging (primordial), preventing disease (primary), detecting it early (secondary), limiting disability (tertiary) and avoiding over-medicalisation (quaternary).
The Leavell and Clark model
In the late 1950s Hugh Leavell and E. Gurney Clark described prevention across the natural history of disease. Their model remains a standard in public health teaching.
The five levels with examples
Primordial: policies that keep risk factors from appearing, such as tobacco advertising bans and safe playgrounds. Primary: vaccination, handwashing, bed nets and condoms. Secondary: screening such as blood-pressure checks, Pap smears or VIA for cervical cancer. Tertiary: rehabilitation after stroke, diabetic foot care. Quaternary: protecting patients from unnecessary tests and treatment.
Choosing the right level
Earlier prevention is usually cheaper and benefits more people. Nepal's PEN (Package of Essential NCD interventions) combines primary prevention counselling with secondary screening for hypertension and diabetes at health posts.
Key takeaways
- Vaccination is primary prevention.
- Screening is secondary prevention.
- Rehabilitation is tertiary prevention.
Common questions
Is health education primary prevention?
Yes, when it aims to stop disease before it starts.
What is quaternary prevention?
Protecting people from harm caused by excessive or unnecessary medical intervention.
References
Educational content by PHC-Nepal. It does not replace advice from a qualified health professional.