Nature of Disease

Nature of Disease

Natural history of disease refers to the progress of a disease process in an individual over time in the absence of intervention. The process begins with exposure to or accumulation of factors capable of causing disease. Without medical intervention, the process ends with recovery, disability, or death.

Knowledge of the natural history of disease ranks along side causal understanding in importance for disease prevention and control.

The Natural History of Disease in a Patient

·           A –  Biologic onset of disease

·           P – Pathologic evidence of disease if Sought

·           S – Signs and symptoms of disease

·           M – Medical care sought

·           D – Diagnosis and

·           T – Treatment

Levels of Disease Prevention

A. Primary Prevention

·           Measures of prevention undertaken before an individual experiences health problem.

·           Health education programme immunization, physical and nutritional fitness activities.

B. Secondary Prevention

Measures of prevention focuses on individual experiencing health problem without symptoms and who are at risk for developing complications.

PREVENTIVE MEASURES: Early diagnosis and treatment. Eg. Medical examination of school children.

C. Tertiary Prevention

Measures undertaken when the disease has become advanced in order to prevent disabilities and to help individual to achieve has high level of functioning. Eg. Application of plaster for fracture to prevent further complication.

Disease Occurrence

Disease is not simply cost by a single factor but it results from interaction of three factors. The host, The Agent and the environment.

The interaction of three factors the Host, Agent, and the environment. The interaction of these three factors are called the epidemiological triad of disease.

Presence of only one of this factors is not enough to cause the disease. These factors must interact in a particular way to lead to the disease.

An Agent: Is an environment factors are stressor that must be present or absent for an illness to occur. Eg. Bacteria, Virus, Dust, Toxins, Insecticides. Heat, Cold, Sound excess or deficient of Vitamins and Minerals.

A Host: Is a living organism capable of being infected or affected by an agent. Eg. Age, Sex, Health habits.

Environment: Is the conditions that. Facilitate the contact between the host and the agent. Eg. Temperature, air, Viruses, Insects, Animals, Plants, Cultural values habits, life styles

Eg. Burns

Host: Susceptible person

Agent: Physical/Chemical agent

Environment: Conditions for Exposure/ Injury

Kerosene are present in all houses and the children are at risk, but all children will not get burned. This depends are interaction between the home environment and the children.