Human Health and Disease: Conditions, Prevention, and Treatment
Health and Disease
Concept of Health and Disease
The World Health Organization defines health as a state of complete physical, mental, and social well-being. Disease is an altered state of health, implying the permanent loss of physical, mental, or social well-being.
Quality of Life and Life Expectancy
The quality of life is defined by a person’s prosperity, happiness, and satisfaction, enabling them to act. This quality depends on physical and mental autonomy, social relationships, and environment. Life expectancy at birth estimates the average years a group of people born in a year would live, assuming health and social conditions remain constant.
Genes, Lifestyle, and Health
Genetic diseases are alterations in the genome, such as Down syndrome. Congenital diseases manifest at birth due to disturbances during embryonic development or childbirth.
Types of Diseases
Infectious and Parasitic Diseases
Examples include influenza and AIDS.
Tumors
Can be benign or cancerous.
Blood Disorders
Such as anemia and coagulopathies.
Endocrine, Nutritional, and Metabolic Diseases
Including diabetes, obesity, and mental depression.
Nervous System Diseases
Examples are meningitis and Parkinson’s disease.
Sensory Organ Diseases
Such as blindness and bronchitis.
Asthma
A respiratory condition.
Chemical Environmental Insults
Carbon monoxide is very toxic to humans. Nitrogen oxide and particulate matter cause respiratory diseases and lung problems. Water pollution includes domestic and industrial waste.
Organic Pollutants
Raw sewage and livestock waste.
Inorganic Pollutants
Nitrates and phosphates from fertilizers, acid salts, and toxic metals.
Transmission of Infectious Diseases
- Direct contact: Skin diseases like leprosy, respiratory diseases spread through sneezing, and sexually transmitted diseases like AIDS.
- Waterborne: Such as salmonella.
- Foodborne: Such as fever.
- Animals: Such as malaria.
Development of Infectious Diseases
- Infection: Microorganisms reach the body, penetrate, and start to reproduce (e.g., HIV).
- Incubation period: Time from infection until symptoms appear (influenza has short periods, AIDS has long periods).
- Acute period: The disease fully manifests with symptoms like fever and chills.
- Decline period: Symptoms decrease as the body defeats the pathogen or medication takes effect.
- Convalescence: The patient recovers strength and returns to health.
Prevention of Infectious Diseases
- Do not drink water from potentially contaminated sources.
- Properly store and handle food.
- Heat prepared food thoroughly.
- Wash and boil vegetables.
- Wash hands after using the toilet and before eating or handling food.
- Use condoms during sex.
Defense Mechanisms
Nonspecific defense mechanisms defend against any infection. Specific defense mechanisms target specific microorganisms, identifying and developing a targeted defense strategy.
Nonspecific Mechanisms
Skin, mucous membranes, and inflammation.
Specific Mechanisms: The Immune System
The most important components are white blood cells called lymphocytes.
Treatments
Diseases Caused by Protozoa and Fungi
Malaria, caused by a protozoa transmitted by mosquitoes, was effectively treated with quinine from tree bark.
Viral Infections
Viral infections are difficult to treat; the body must create its own defenses.
Vaccines
Vaccines immunize against microbial pathogens. Smallpox, characterized by pustules, is combated through vaccination.
Malignancy
Malignant cells can move from the initial location and generate new tumors elsewhere in the body. This involves invasiveness and metastasis.
Genetics and Cancer
Cancer can have genetic origins.
Cancer Treatment
- Surgery: Removing the tumor mass.
- Radiotherapy: Using radiation to destroy cancer cells.
- Chemotherapy: Administering drugs to kill cancer cells.
- Hormonal Treatments: Effective in cancers that require hormones to grow.
- Immunotherapy: Enhancing the immune system to remove the tumor.
Metabolic Disorders
Diabetes Mellitus
Caused by insulin dysfunction.
Obesity
Caused by excessive fat accumulation.
Cardiovascular Diseases
Heart disease and myocardial infarction (heart attack) occur when part of the heart muscle lacks blood supply. A stroke happens when blood supply to part of the brain is cut off.
Risk Factors for Cardiovascular Disease
- Non-modifiable: Age, male gender, family history.
- Modifiable: Smoking, hypertension, diabetes, high cholesterol.
Respiratory Diseases
Obstructive pulmonary disease: Narrowing or obstruction of airways reduces exhaled air volume. Restrictive disease: Reduced lung elasticity decreases total air volume. Lung cancer: Pneumothorax (holes in the lungs).
Mental Illness
- Schizophrenia: Distorted reasoning and hallucinations.
- Anxiety Disorders: Intense fear or dread.
- Depression: Sadness and disinterest in activities.
- Eating Disorders: Anorexia nervosa (obsession with being thin) and bulimia (binging and purging).
- Attention Deficit Hyperactivity Disorder (ADHD): Problems controlling energy and attention.
- Personality Disorders: Rigid and inappropriate behavior patterns.
- Dementia: Progressive loss of mental capabilities.
Addictive Behaviors
Addiction causes behavioral changes. Substance abuse interferes with normal life, and dependency involves spending significant time obtaining and using drugs.
Drugs
Drugs are substances that alter brain function. They are classified into nervous system depressants, stimulants, and perturbators.
Diagnostic Techniques
Imaging
- X-ray: The first imaging technique.
- Computed Tomography (CT): Multiple X-rays from one area.
- Magnetic Resonance Imaging (MRI): Uses magnetic fields.
- Ultrasound: Uses high-frequency sound waves.
Cardiac Catheterization
A thin tube is introduced through an artery to the heart.
Techniques to Record Electrical Activity
- Electrocardiogram (ECG): Electrical activity of the heart.
- Electroencephalogram (EEG): Electrical activity of the brain.
- Electromyogram (EMG): Electrical activity of muscles and nerves.
Endoscopic Techniques
Visualizing the body’s interior by introducing an endoscope through an orifice or small incision.
Biopsy
Extracting a small tissue piece for laboratory examination.
Is Health a Universal Right?
International agencies recognize the right to health. Public health systems exist to ensure healthcare, but this right is not universally practiced.