Overview
This lecture covers the five periods or stages of disease, explaining what occurs at each stage and their implications for disease transmission.
Stages of Disease
- Most diseases follow a five-step process: incubation, prodromal, illness, decline, and convalescence.
- The incubation period is when you are infected but don't show any disease symptoms.
- Incubation duration varies greatly (hours to years) depending on the disease.
- The prodromal period features mild signs or symptoms indicating the onset of disease.
- The period of illness is when symptoms are most severe and you are at your sickest.
- The period of decline is when symptoms lessen and you begin to recover.
- The period of convalescence is when you regain strength, though full energy may not yet be restored.
Disease Transmission
- Diseases can be spread during any stage, including incubation and convalescence.
- Transmission is most likely during the illness and decline periods but possible before and after symptoms.
Key Terms & Definitions
- Incubation period — Time when infected but not yet showing disease symptoms.
- Prodromal period — Stage with mild, early symptoms signaling the start of illness.
- Period of illness — Stage with the most severe symptoms; peak of sickness.
- Period of decline — Stage where severe symptoms subside and recovery begins.
- Period of convalescence — Stage of regaining strength and final recovery, though not fully energized.
- Homeostasis — The body’s ability to maintain a stable internal environment.
Action Items / Next Steps
- Review the five stages and be able to define and distinguish each for upcoming exams.