Understanding Health, Diseases, and Treatments
Health and Sickness
The Decline of Infectious Diseases
The decline of infectious diseases is primarily due to the availability of clean drinking water, effective sanitation networks, and good nutrition. Life expectancy in developed countries has doubled in the last 80 years due to advancements such as antibiotics, vaccines, and other medical and health achievements.
Personal Conditions for a Good Old Age
- Consume alcohol in moderation
- Avoid smoking
- Maintain a stable partner
- Engage in physical exercise
- Stay active
- Pursue education
- Cultivate a positive attitude towards challenges
Bacteria
Bacteria are single-celled organisms without a membrane-bound nucleus. They can be classified based on their shape:
- Cocci: Spherical shape
- Bacilli: Long and cylindrical
- Spirilla: Spiral
- Vibrios: Comma-shaped
Bacteria can be pathogenic (disease-causing) or non-pathogenic. They play a role in fermentation, genetic engineering, and the production of pharmaceutical products.
Viruses
Viruses can only survive by entering the cells of another living being.
Antibiotics: Penicillin
Penicillin was discovered by Alexander Fleming. Upon returning from vacation, he observed that a petri dish containing staphylococci had been contaminated with a white circular mold. The bacteria surrounding the mold had disappeared. Fleming deduced that the mold was producing a substance that killed the staphylococci, which he named penicillin.
Infection Control
AIDS
Researchers suspected that AIDS was caused by a virus because it was transmitted from person to person through sexual contact and blood. HIV destroys the human immune system by attacking white blood cells. The virus is present in bodily fluids such as blood, semen, vaginal fluids, and breast milk. It can be spread through sexual intercourse, sharing needles, razors, or during pregnancy, childbirth, and breastfeeding. It cannot be spread through kissing, touching, coughing, or mosquito bites.
Tenacious Adversaries
Diseases like tuberculosis can remain dormant in the body. If the immune system weakens, the disease can become active.
Pandemics
When an infectious disease surpasses geographical barriers and spreads across the globe, it is considered a pandemic.
Cancer Out of Control
Sometimes, cells begin to multiply uncontrollably and lose their ability to specialize and perform their intended functions. This uncontrolled growth produces a tumor. When a malignant tumor progresses, the cells can metastasize through blood vessels and the lymphatic system. Bacteria, viruses, and toxic chemicals were the first identified causes of cancer. Ultraviolet radiation from the sun is linked to skin cancer, smoking is linked to lung cancer, the hepatitis B virus is linked to liver cancer, uranium is linked to leukemia, and the herpes virus is linked to uterine cancer.
Treatment for Cancer
- Surgery: Involves the surgical removal of the tumor.
- Radiotherapy: Uses concentrated radiation to destroy the tumor.
- Chemotherapy: Employs medications to attack cancerous cells.
Cardiovascular Diseases
Cardiovascular diseases are largely caused by an unbalanced diet, lack of physical exercise, excessive stress, and smoking.
Heart Ailments
Heart ailments are a group of diseases that affect the heart and blood vessels.
- Bypass: A surgical procedure that creates a detour around a blocked artery using a graft.
- Angioplasty: Involves inserting a balloon catheter into a blocked artery and inflating it to widen the artery.
- Beta-blockers: Medications that reduce the heart rate and are used to treat hypertension, stabilize the heartbeat, and prevent angina.
Mental Illnesses
Examples of mental illnesses include Alzheimer’s disease, schizophrenia, depression, anorexia, bulimia, and vigorexia.
Diagnostic Treatments
X-rays
X-rays can penetrate soft tissues of the body, such as skin, fat, and muscle. They are used to detect cancer.
Computed Tomography (CT) and Magnetic Resonance Imaging (MRI)
CT scans generate images of cross-sections of the body. MRI provides detailed images of any part of the human body using a strong magnetic field and radio waves.
Positron Emission Tomography (PET)
The patient is injected with a slightly radioactive glucose that emits positrons. The patient then enters a ring of detectors that record the positrons, creating a color image that represents different levels of cellular activity in the tissues.
Thermal Imager
Useful for detecting tumors by identifying temperature differences in the body.
Bone Densitometry
Used to determine bone density.
Transplants
Rejection is controlled with immunosuppressive drugs. However, this can increase the risk of infections from opportunistic organisms.
Death Determination
Previously, cardiac arrest was considered the sign of death. The Harvard criteria now define death as a flat electroencephalogram, indicating irreversible cessation of brain function.
Insulin
Insulin is a low molecular weight protein composed of 51 amino acids linked in two chains. It allows tissues to absorb, store, and utilize glucose. It also affects fat and protein metabolism.
Diabetes
Diabetes is a disease that can lead to death. The pancreas, a gland near the stomach, produces a juice that is released into the small intestine to break down food molecules into nutrients that can be absorbed by the body.
Determinants of Health
Environment
- Physical Contaminants: UV radiation, radioactivity, noise, dust, volcanic eruptions.
- Chemical Contaminants: Gases, dioxins, pesticides, heavy metals, detergents.
- Biological Contaminants: Viruses, bacteria, protozoa, fungi, arthropods, and other parasites.
Healthy Habits and Lifestyle
- Regular exercise
- Avoid smoking
- Reduce alcohol consumption
- Avoid drugs
- Maintain a balanced diet
- Practice safe sex
- Maintain personal hygiene
- Protect yourself from the sun
Biological Factors
- Aging
- Hereditary factors
Healthcare System
The way a country organizes and finances health protection and provides medical services to its citizens. Features include universal coverage, funding through income-based taxation, and ensuring equal access to resources and services.
Types of Disorders
According to Factors
- Communicable Diseases: Caused by microorganisms and animal parasites.
- Non-communicable Diseases
By Duration
- Acute
- Chronic
When Developed
- Congenital
- Acquired
Time and Place
- Sporadic
- Endemic
Amplitude
- Epidemics
- Pandemics
Forecast
- Benign
- Malignant
Sources of Infection
Direct Transmission or Contagion
Occurs through direct contact between an infected and a healthy person. Transmission can be physical or through the release of infectious particles.
Indirect Transmission
Germs from the source of infection are passed through a medium, such as water or food, to a healthy person.
Reservoirs
Animals that harbor infectious agents that can be transmitted to humans.
White Blood Cells
Phagocytes
Engulf and digest foreign bodies, such as bacteria.
Lymphocytes
The most abundant type of white blood cells. There are two types: B lymphocytes, which produce antibodies, and T lymphocytes, which destroy viruses or cells infected by cancer.
Immunity
Active Immunity
Develops after contact with an antigen, either through contracting a disease (natural) or through vaccination (artificial).
Passive Immunity
Acquired through maternal antibodies during pregnancy or breastfeeding (natural) or through the administration of serums (artificial).
Emerging Diseases
Infectious diseases that appear in specific times and places and become, or threaten to become, new epidemics.