Understanding Diseases: Causes, Types, and Treatments

**We Manage the Disease**

*Pathology*

Pathology, the science of disease, is the basis of diagnosis.

• Etiology studies the causes of diseases.
• Pathogenesis investigates the mechanism of action of the disease.
• Pathological anatomy seeks to know the outcome of the disorder and injuries.
• Pathophysiology analyzes the functional changes that the patient undergoes.

Clinical Signs and Symptoms

The clinic studies the signals that reveal the disease. Signs include pulse, artery pressure, and temperature. Symptoms and investigations provide additional information, such as radiographs.

**Infectious and Parasitic Diseases**

Infectious and parasitic diseases are caused by biological pathogens.

• Incubation is the time from the entry of the pathogen into the body until the first symptoms appear.
• Development is the progression of the disease with symptoms.
• Convalescence is the period that elapses once the disease is overcome until the body regains its initial state.

Types of Infectious Diseases

Types of infectious diseases include prion diseases, viral, bacterial, fungal, parasitic (caused by protozoa), and those caused by metazoans.

**Non-Infectious Diseases**

Cancer

In cancer, when a cell splits, it duplicates its DNA. If there is an alteration, the p53 protein is activated, curbing this division and giving the cell time to repair. Otherwise, apoptosis (programmed cell death) occurs, thus preventing the proliferation of damaged DNA. Sometimes these cells remain alive, grow, and divide to form tumors.

Cancer is treated with surgery, radiotherapy, and chemotherapy.

**Endocrine, Nutritional, and Metabolic Diseases**

Anorexia

Anorexia is characterized by a fear of gaining weight, eating disorders, distortion of body image, and low self-esteem. It occurs primarily in adolescent women.

Bulimia

Bulimia is closely linked to anorexia, and many patients have both conditions. It involves a maladjustment of repeated food intake with excessive and compulsive elements. The individual then induces vomiting, feeling guilty and worried about their appearance.

**Cardiovascular Diseases**

Cardiovascular diseases affect the heart and blood vessels.

• Stroke occurs when a part of the brain loses its blood supply and therefore oxygen, often due to a thrombus.
• Heart attack is caused by a coronary artery obstruction, leading to a lack of oxygen and the death of part of the heart muscle.
• Arteriosclerosis is the hardening of artery walls, increasing blood pressure.
• Hypertension occurs when blood pressure is higher than normal.