Comprehensive Health and Disease Insights

Understanding Health and Disease

Key Definitions

• Disease: A part of our body that changes and ceases to perform its function well.
• Health: Your mental or physical condition.
• Symptoms: A physical or mental feeling experienced by someone with a disease or illness.
• Diagnose: To study symptoms of an illness or disease and to decide what is wrong with a person.
• Sign: A symptom of a disease or illness that is recognized by others.
• Treatment: Medical care or attention given to a person who is ill (curative or symptomatic).
• Convalescence: The period needed for returning to health after illness.

Factors for Maintaining Good Health and Preventing Diseases

• A Healthy Environment: Free of anything harmful to health.
• Healthy Habits and Lifestyles.
• Personal Characteristics.
• An Efficient and High-Quality Healthcare System.

Types of Diseases

By Origin

• Infectious: Caused by pathogens (e.g., Rabies, Measles, Flu).
• Non-infectious: Not caused by pathogens (e.g., Cancer, Depression).

By Appearance and Duration

• Acute: Develops rapidly and lasts a short time (e.g., Flu).
• Chronic: Develops slowly and lasts a long time (e.g., Arthritis, Diabetes).

By Incidence in Population (Epidemiology)

• Sporadic: Occurs occasionally and irregularly (e.g., Strokes, Heart Attack).
• Endemic: Constantly present in a population (e.g., Malaria, Plague).
• Epidemic: A widespread occurrence of an infectious disease in a community at a particular time (e.g., Flu).
• Pandemic: An epidemic that has spread across a large region, multiple continents, or worldwide (e.g., AIDS).

Microorganisms and Infectious Diseases

• Bacteria: Single-cell prokaryotic organisms with no organelles or nucleus (e.g., Diphtheria, Pneumonia).
• Protozoa: Eukaryotic single-cell organisms (e.g., Malaria, Sleeping Sickness).
• Fungi: Eukaryotic single-cell or multicellular organisms (e.g., Candidiasis, Athlete's Foot).
• Viruses: Non-cellular infectious agents (e.g., Chickenpox, Polio Virus).

Transmission of Diseases

• Direct Contact: Such as sexually transmitted diseases.
• Inert Objects (Fomites): Like those spreading colds or flu.
• Contaminated Water: (e.g., Cholera).
• Contaminated Food: (e.g., Salmonellosis).
• Airborne Transmission: (e.g., Tuberculosis).
• Contact with Animals (Vectors): (e.g., Sleeping Sickness, Malaria).

Body Defenses Against Disease

These are the body's mechanisms to protect against illness.

External Defenses

• Structural: Skin, mucous membranes, digestive and respiratory tracts.
• Biochemical: Saliva, tears, and gastric juices.
• Mechanical: Cilia (tiny hair-like structures).
• Ecological: Non-pathogenic microorganisms that compete with harmful ones.

Internal Defenses (Immune System)

• Non-specific Defenses: Act against any type of microorganism or foreign particle. This is carried out by phagocytosis, a process where cells engulf foreign particles.
• Specific Defenses: Act selectively against specific microorganisms or foreign molecules. Lymphocytes carry the necessary proteins, which are specific for each type of microorganism, providing targeted immunity.

Phases of Infectious Disease Spread

• Incubation Phase: The period between pathogens invading an organism until symptoms appear.
• Apparent Disease Phase: Symptoms and signs appear, indicating active illness.
• Convalescence Phase: Pathogens have been eliminated, and the body begins to repair damage.
• Recovery Phase: The body fully recovers and returns to a healthy state.