Understanding Infectious and Non-Infectious Diseases
Infectious Diseases
Pandemic
A pandemic is a global outbreak of an infectious disease caused by bacteria or a little-known virus that crosses geographical barriers. Example: The Black Plague.
Epidemic
An epidemic is an infectious disease caused by a bacteria, virus, or other pathogen, usually affecting large, specific regions. Example: Influenza A.
Endemic
An endemic is an infectious disease caused by a virus or bacteria that is consistently present within a specific region. Example: Seasonal influenza.
Non-Infectious Diseases
Cancer
Cancer occurs when cells grow uncontrollably and lose their ability to specialize and perform their intended function within a specific tissue or organ. This uncontrolled growth causes tumors. Some tumors are small, while others grow rapidly and destroy surrounding healthy cells; these are malignant tumors. As malignancy progresses, cancer cells spread throughout the body (metastasize) via blood vessels and the lymphatic system.
Often regarded as a 20th-century disease, cancer is a leading cause of death worldwide.
Causes and Treatments
Cancer is caused by mutagenic agents (factors that cause DNA mutations, such as radioactive contaminants) and hereditary factors (5% of cancers are hereditary).
- Surgery: Surgical removal of the tumor. Advances in technology like scanners, ultrasound, and MRI have improved early detection and surgical precision.
- Radiotherapy: Applying concentrated doses of radiation to destroy the tumor. Linear accelerators produce thin beams of radiation that penetrate deeper areas without damaging surrounding tissues.
- Chemotherapy: Using drugs to attack cancer cells. Interferons, proteins produced by the body, can inhibit uncontrolled cell growth. Chemotherapy’s cytotoxic effect impacts not only malignant cells but also rapidly proliferating tissues (skin, mucosa, etc.).
Health officials recommend preventive measures such as avoiding tobacco, protecting oneself from the sun, and consuming foods rich in beneficial fatty acids like olive oil.
Cardiovascular Diseases
Cardiovascular diseases are largely caused by an unbalanced diet (cholesterol accumulation in the veins), lack of physical exercise, stress (leading to hypertension), and tobacco use (arteriosclerosis). These factors contribute to cardiovascular diseases being a leading cause of death globally.
Cardiovascular diseases encompass a group of disorders affecting the heart and blood vessels, including changes in the heart muscle, valves, and blood vessels supplying the heart and brain, as well as hypertension. Heart attacks and strokes are major cardiovascular events caused by blocked blood flow to the heart or brain. This blockage is usually due to the narrowing of arteries and veins by fat accumulation. Strokes can also be caused by bleeding in the brain.
Medical advancements have significantly improved the treatment of cardiovascular diseases. Blocked arteries can be treated with bypass surgery (creating a bridge around the damaged artery) or angioplasty (inserting a balloon catheter to widen narrowed arteries).
Mental Illness
Mental illnesses encompass a range of conditions, including depression, euphoria, sadness, anxiety, fear, Alzheimer’s disease, and psychosis. Persistent experiences of these emotions or states can indicate a mental health condition.
Determining if someone has a mental illness and identifying the specific disorder is a significant challenge in medicine. Some disorders, like Alzheimer’s disease (characterized by memory loss and dementia in old age), have identifiable causes. Schizophrenia, affecting 1% of the population, involves distorted reality, hallucinations, delusions, and auditory hallucinations.
Drug use (LSD, cocaine, ecstasy, cannabis) can increase the risk of mental illness, although it is not the sole determining factor. Depression, characterized by prolonged and disabling sadness, is a well-known mental illness. Bipolar disorder involves alternating episodes of intense melancholy and euphoria.
Eating disorders are also related to mental health:
- Anorexia: A distorted body image and a feeling of lacking control lead to extreme thinness, often through fasting.
- Bulimia: Cycles of binge eating followed by purging through vomiting and laxatives.
- Vigorexia: An obsession with muscularity, despite being already very muscular, leading to a constant feeling of weakness.
Pharmacological treatments include mood stabilizers, antipsychotics (reducing distorted reality), and antidepressants. Psychotherapy helps individuals recognize and address their problems, providing resources to cope with and overcome them.