Understanding Health, Diseases, and Treatments: A Comprehensive Guide
1. Health and Disease
Concept of Health and Disease
Health is defined as a state of complete physical, mental, and social well-being, not merely the absence of disease. Disease is defined as an altered state of health, a temporary or permanent loss of physical, mental, or social well-being.
Quality of Life and Life Expectancy
The quality of life of a person is defined as the degree of comfort, happiness, and satisfaction that allows them to experience and feel life positively. One of the main indicators of quality of life is life expectancy at birth.
Genes, Lifestyle, and Health
Genetic diseases are due to alterations in the genome. The genetic defect is the direct cause of the disease. In other cases, it is an inherited predisposition to the disease. If you take good care of yourself, you may not develop it. Congenital diseases are manifested at birth, due to some disorder during pregnancy or childbirth. Today, they are detected before birth and sometimes can even be cured.
2. Aggressions and Health Risks
Health is subject to several diseases, aggressions, and risks that may originate in different areas: the environment around you, the sociocultural environment, everyday habits, and within the body (internal).
The Diseases That Affect Us
Diseases are classified according to criteria such as location or cause. The most useful classifications use two main categories.
Environmental Insults
There are three types of environmental insults: physical, chemical, and biological.
Physical Insults
- Ionizing Radiation: A form of energy capable of modifying the structure of matter, potentially causing changes in our cells, some of which may alter our health.
- Noise: Sound that can cause sleep and behavior disturbances and hearing loss.
- Temperature Variations: High temperatures combined with high humidity prevent sweat evaporation and can be lethal. Extreme cold can also be harmful.
Chemical Insults
- Air Pollution: Human activities change the composition of air, adding compounds that affect health. Air is often polluted with carbon monoxide, sulfur dioxide, nitrogen oxides, and particulate matter.
- Water Pollution: Domestic and industrial water use degrades water with organic, inorganic, and biological pollutants.
- Food Contamination: Food is contaminated when foreign substances are present. When eaten, these substances can have negative effects on our bodies. In some cases, the effects are not seen in the short term, but the pollutant can accumulate and cause the development of a disease.
3. Infectious Diseases
Pathogens
Infectious diseases are caused by microorganisms: bacteria, viruses, protozoa, and fungi. In nature, many living organisms exist, mostly harmless to us. Those that can cause disease are called pathogens.
Transmission of Infectious Diseases
For an infectious disease to manifest, the organism must penetrate the body. This happens in several ways:
- Direct Contact: The organism is passed from one ill person to a healthy one by various methods: skin diseases through skin contact, respiratory diseases through droplets produced by sneezing, and sexually transmitted diseases.
- Waterborne: Occurs if the water is contaminated with fecal matter.
- Foodborne: Occurs when food is irrigated with polluted water or handled improperly.
- Vector-borne: Animals that can transmit diseases are called vectors.
Development of Infectious Diseases
An infectious disease follows several stages:
- Infection: The organism enters the body, penetrates inside, and begins to multiply.
- Incubation Period: The time from infection until symptoms begin to appear.
- Acute Period: The disease is fully manifested.
- Period of Decline: The disease symptoms are easing, either because our body is fighting it off or because we are taking medication.
- Convalescence: The patient is regaining strength until they return to being healthy.
Prevention of Infectious Diseases
The best way to prevent disease is to try to prevent transmission by adopting certain habits:
- Do not drink water from streams or sources that may be contaminated.
- Store and handle food according to the rules that appear on their packaging.
- Heat food well and, if possible, boil prepared food.
- Wash vegetables, fruits, and vegetables that are to be eaten raw.
- Wash hands after going to the toilet and before eating or handling food.
- Use condoms during sexual intercourse. This will prevent unwanted pregnancies and sexually transmitted diseases.
4. Defense Against Infections
4.1 Defense Mechanisms
Nonspecific Defense Mechanisms: Defend us against any infection.
Specific Defense Mechanisms: Are directed against each specific microorganism that comes into contact with us.
4.2 Nonspecific Mechanisms
- Skin: An impenetrable barrier for most microorganisms.
- Mucosa: Epithelia lining the body cavities in contact with the outside.
- Inflammation: The body’s response to microorganisms or foreign particles before they reach the inside.
4.3 Specific Mechanisms: The Immune System
The most important component of the immune system are white blood cells called lymphocytes found in the blood. These cells can recognize microorganisms or any foreign element in our body.
- B Lymphocytes: Produce antibodies, which are proteins, also called immunoglobulins, that bind to antigens.
- T Lymphocytes: When a virus infects a cell, proteins from its envelope are displayed on the cell surface. T lymphocytes recognize these proteins, which act as antigens, and destroy the infected cells.
4.4 Disorders of the Immune System
- Autoimmune Diseases: Occur when the immune system recognizes as foreign any molecule of our own body.
- Allergies: Appear when the immune system responds to antigens that it should not normally respond to.
5. Treatment of Infectious Diseases
5.1 Treatment Against Diseases Caused by Bacteria
Bacterial infections are treated with antibiotics, which are substances toxic to bacteria. Alexander Fleming discovered the first antibiotic in 1928.
5.2 Treatment Against Diseases Caused by Protozoa and Fungi
For the treatment of infections by protozoa and fungi, antiprotozoal and fungicidal medications are used, respectively.
5.3 Virus Treatment
Viral infections are more difficult to treat because once the virus is introduced into the cells, it is difficult to eliminate. Some medicines can alleviate the symptoms, but ultimately, it is our own body that must fight the infection and eliminate the virus.
5.4 Vaccines
Vaccines are used to immunize people against several pathogenic microorganisms. Vaccines work by stimulating our immune system to develop antibodies that can counteract a virus or bacterium that invades our body and produce memory cells.
6. Tumor Diseases and AIDS
6.1 What is a Tumor?
In normal tissues, cells are dividing to produce new cells to replace those that are old and worn out. Sometimes this balance is upset, and in such cases, a tumor develops where cells are produced more than necessary or old cells do not die when they should.
Most tumors are benign.
6.2 Malignant Tumors
Cancer is a major cause of death. A malignant tumor is one whose cells can move from the initial tumor site to generate new tumors in other body parts.
- Invasiveness: Ability to penetrate and spread throughout the tissues.
- Metastasis: The ability to penetrate into the blood and lymph vessels, move through the blood and lymph, and deposit anywhere in the body to form a secondary tumor.
6.3 Genetics and Cancer
The body’s cells divide many times. In each division, the DNA is duplicated. Errors during this process may lead to mutations.
6.4 Cancer Treatment
- Surgery: The removal of the tumor mass.
- Radiotherapy: Involves the utilization of radiation to destroy cancer cells.
- Chemotherapy: Consists of the administration of drugs that kill cancer cells.
- Hormone Treatments: Are effective in some cancers that require the presence of hormones to develop.
- Immunotherapy: The use of agents that stimulate the immune system, which would then take care of removing the tumor.