Understanding Health, Disease, and Their Indicators
Theme 1: Health and Disease
1. Health and Disease
1.1. Introduction
Defining the concept of health is not easy, yet it is universally understood. Its meaning has changed significantly throughout history, from prehistoric humans with a magic-religious view of life to the scientific and rational humans of modern times. It has been widely believed that health is the absence of disease. However, this is a vague concept, as many situations exist where it’s impossible to establish a clear boundary between health and disease.
Furthermore, it often happens that a person feels healthy and believes they are in good health but suffers from an undiagnosed disease (like hypertension). Conversely, some people feel weak and sick, but objectively, there is no discernible alteration or imbalance in their body.
1.2. Concept of Health
Formerly, health was defined as the absence of disease and disability. This definition is inaccurate because it requires establishing boundaries between healthy and sick, which may not be consistent across all societies and times. For example, obesity was previously considered a sign of health, while today it is a treated disease.
The World Health Organization (WHO) defines health as: a state of complete physical, mental, and social well-being, not merely the absence of disease.
This definition is characterized by:
- Being very utopian: it requires achieving a state of completeness in all areas and considering the dynamic nature of individuals and their health. A person can fluctuate between different degrees of health without reaching complete well-being, and we cannot say they are unhealthy because of it.
- Being subjective: it depends on what each person considers well-being. Two people can be in the same physical and social state but have different perceptions of their well-being. Therefore, one person could consider themselves healthy, and the other might not.
Under this definition, a person who stayed up all night and didn’t sleep well, or someone who has lost a loved one or been cheated in a home purchase, could be considered unhealthy. However, euphoric drug addicts under the influence of drugs, or individuals with an infectious disease or a tumor in the early stages without symptoms, could consider themselves healthy.
1.3. Health and Indicators
Physical health is determined by studying a person’s most important physiological parameters. These parameters indicate:
- The operational status of each organ, apparatus, and system in our body.
- The degree of coordination between them.
The most frequently studied parameters are vital signs, which include:
- Body Temperature: The human body temperature is very stable because it is controlled by a regulatory mechanism located in the hypothalamus of the brain. Its value ranges around 37°C.
- Weight: It indicates the degree of normality in the body. Reference values vary according to height, sex, age, and body type (athletic, intermediate, and fleshy). Weight should be determined while fasting, barefoot, and with minimal clothing.
- Pulse: It results from pressure variations during the cardiac cycle, causing the expansion and contraction of artery walls. It’s a method for determining heart rate and abnormal rhythms.
- Blood Pressure: It’s the blood pressure inside the major arteries, where it reaches its maximum values. This pressure is not constant during the cardiac cycle, so maximum and minimum pressures can be determined.
- Vital Capacity: This parameter represents the maximum volume of air that can be exchanged in one lung ventilation cycle (inspiration and expiration). Vital capacity is highly variable and depends on the individual’s anatomical and physiological characteristics.
- Hemogram: It is a set of analyses performed on:
- Blood cells (erythrocytes and leukocytes)
- Platelets
- Plasma Chemistry Composition: Determining plasma components indicates the effectiveness of various metabolic processes (intestinal absorption, excretion, liver function, etc.) that occur in the body.
- Urine Chemistry Composition: The chemical analysis of urine provides data on the effectiveness of the excretion process carried out by the kidneys.
2. Concept of Disease
The dictionary defines disease as an alteration or deviation from the physiological state of the body or its parts, manifested by characteristic symptoms or signs that could lead to a decline in life. Thus, as with health, disease has a subjective aspect (what the patient feels, which are symptoms) and an objective side (signs, which are the outward manifestations).
Disease can be defined as:
An organic or functional impairment that negatively affects a person’s state of well-being.
Classification of diseases by cause:
- Traumatic: Produced by fractures or injuries to the skeletal muscle system. These include sprains, dislocations, and fractures.
- Environmental: Caused by the physical environment (cold, heat, radiation). Heatstroke and frostbite are clear examples of environmental diseases.
- Toxic: Caused by the ingestion or inhalation of harmful products or permissible products in amounts exceeding the tolerance limit. For example, poisoning by chemicals, ingestion of poisonous mushrooms, or animal bites.
- Infectious: A significant group of diseases commonly caused by an infectious agent (virus, bacteria, fungi, etc.). They can spread from person to person, leading to outbreaks. Examples include tuberculosis and cholera.
- Metabolic: Alterations in metabolism, either due to inheritance or nutritional imbalances. Examples include diabetes and gout.
- Degenerative: Originate from anatomical and functional alterations in the tissues of any organ, vessel, or organ system. For example, myocardial infarction due to necrosis of a portion of the heart caused by coronary artery blockage.
- Neoplastic: Characterized by the abnormal proliferation of cells in an organ. For example, cancer.
- Mental: Affect behavior and mental condition. They can be caused by:
- Organic brain injury (e.g., psychosis and dementia)
- Unknown anatomical basis (e.g., phobias)