Health and Disease Prevention

Health, Sickness, and Prevention

• Health involves physical, mental, and social well-being.
• Disease is defined as an imbalance in the body's equilibrium, disrupting normal functioning.
• Homeostasis is the state of equilibrium in the body needed to maintain life.
• Glucose levels in the blood are regulated by insulin and glucagon.
• Factors influencing disease and health include host factors (genetics, gender, age, immunity, nutrition, etc.), disease-causing agents (bacteria, viruses, etc.), and environmental factors.
• Examples of disease-causing agents include viruses, bacteria, fungi, protozoa, and helminths.
• Physical agents influencing disease include temperature changes, pressure of gases and liquids, mechanical effects, electricity, and radiation.
• Chemical agents that can harm organisms include toxic substances (pesticides, metals) and nutritional element deficiencies (iodine, vitamin C, iron).

Natural History of Disease and Levels of Prevention

• Disease development follows a natural history, encompassing pre-pathogenic, pathogenic, and convalescence periods.
• Environmental factors play a role in the pre-pathogenic period.
• Disease-causing agents interact with a susceptible host.
• The pathogenic period includes early pathogenesis (unobserved changes), clinical signs/symptoms, disease stage, and convalescence.
• Disease can lead to recovery or chronic disease and sometimes death.
• Prevention strategies are categorized as primary, secondary, and tertiary.
• Primary prevention aims to prevent disease before it occurs.
• Secondary prevention aims to detect and treat diseases early on.
• Tertiary prevention involves managing the outcomes of illness or disease.

The Immune System (1.3)

• A human body is a complex conversation between cells.
• The immune system defends against disease-causing agents.
• Cells involved include specific cells that eat antigens and B cells (lymphocytes) that release antibodies.
• The immune system helps maintain homeostasis.