Health, Disease Origins, and Immune System Functions
Defining Health and Quality of Life
Health is a state of complete physical, mental, and social well-being, not only as the absence of disease. Disease is defined as impaired health or a transient loss of physical, psychological, or social well-being.
Quality of life refers to the happiness and comfort level; it is the satisfaction that allows one to act and feel their life positively. This depends on their physical and mental level of autonomy and social relationships with their environment.
Classifications and Origins of Diseases
Genetic and Congenital Conditions
- Genetic diseases: These are alterations in the genome where the genetic defect is the direct cause of the disease. Examples include Hemophilia, Down syndrome, and some forms of diabetes.
- Congenital diseases: These are those that manifest from birth due to some disorder produced during embryonic development or during childbirth.
The Origin of Diseases
Diseases can originate from the surrounding environment, the own body (internal), living habits, or the social environment.
Mortality Causes and Environmental Factors
Top Three Causes of Mortality in Spain
- Circulatory system diseases (such as stroke)
- Tumor diseases (cancer)
- Diseases of the respiratory system
External Causes of Mortality
External factors include accidents (games, work, falls), poisoning, drug consumption, medical complications, and aggressions.
Environmental Insults and Pollution
- Physical
- Chemical: Air pollution, water pollution, and food contamination.
- Biological: Bacteria, viruses, protozoa, and fungi.
Noise: Unwanted sound is a factor that may induce alterations in sleep and behavior, as well as hearing loss.
Contamination of Food
Contamination occurs when food is ingested with foreign substances present. Even in small amounts, these can have adverse health effects. Pollutants can include pesticide remains and heavy metals. In some cases, the effects are not seen in the short term, but the pollutant can accumulate in the body to cause the development of a disease.
Infectious Diseases and Pathogens
Pathogenic Microorganisms
These are organisms that cannot be observed without the aid of a microscope and cause disease in humans. Examples include Salmonella, the influenza virus, Trypanosoma cruzi (which causes Chagas disease), and fungi that cause ringworm.
Transmission and Stages of Infection
Transmission of infectious diseases: This occurs through direct contact, water, food, or animals.
Infectious stages:
- Infection
- Incubation period
- Period of sharp decline
- Convalescence
The Immune System and Defense Mechanisms
Defense Strategies
- Nonspecific: Any mechanism that defends us against infection generally.
- Specific: Targeting each particular microorganism that contacts us. They identify foreign entities and produce a specific defense strategy.
Immune System Disorders
- Autoimmune diseases: These occur when the immune system recognizes molecules of our own body as foreign. Examples include multiple sclerosis and some types of diabetes.
- Allergies: These occur when the immune system responds to antigens to which it should not normally respond, such as pollen, dust mites, and so on.