Pathophysiology

Pathophysiology studies how disease disrupts normal body function.

• Key terms: etiology (cause), pathogenesis (development), signs (observed) and symptoms (felt).
• Diseases may be acute or chronic, congenital or acquired, infectious or non-infectious.
• Neoplasms are abnormal growths; benign stays local while malignant (cancer) invades and metastasizes.
• Cancer is graded and staged to guide treatment.

Disorders of the skin, hair, and nails.

• The skin protects, regulates temperature, and senses the environment.
• Common conditions: burns, dermatitis/eczema, psoriasis, and skin cancers (melanoma, basal/squamous cell).
• Infections include cellulitis and impetigo.
• Wound healing and pressure ulcers are important clinical concerns.

Disorders of bones, muscles, and joints.

• Fractures, osteoporosis (weak bones), and osteoarthritis (worn cartilage) are common.
• Rheumatoid arthritis is an autoimmune joint disease.
• Muscular dystrophy is a genetic muscle-wasting disorder.
• Sprains, strains, and tendon injuries affect soft tissue.

Disorders of the heart, blood vessels, blood, and lymph.

• Atherosclerosis narrows arteries and can cause heart attack (MI) and stroke.
• Hypertension (high blood pressure) strains the heart and vessels.
• Blood disorders include anemia and leukemia.
• The lymphatic system fights infection; lymphoma and edema affect it.

Disorders that impair breathing and gas exchange.

• Asthma and COPD narrow airways and limit airflow.
• Pneumonia and tuberculosis are infections of the lungs.
• Lung cancer is often linked to smoking.
• Hypoxia (low oxygen) can damage tissues throughout the body.

Disorders of the GI tract and accessory organs.

• GERD, ulcers, and gastritis affect the upper GI tract.
• IBD (Crohn's, ulcerative colitis) and IBS affect the intestines.
• Liver disease includes hepatitis and cirrhosis.
• Gallstones and appendicitis are common surgical concerns.

Disorders of hormone-producing glands.

• Diabetes mellitus (Type 1 and Type 2) disrupts blood glucose control.
• Thyroid disorders include hyperthyroidism and hypothyroidism.
• Cushing's and Addison's affect the adrenal glands.
• Hormone imbalances have body-wide effects.

Disorders of the brain, nerves, and sensory organs.

• Stroke, seizures/epilepsy, and Parkinson's and Alzheimer's disease affect the nervous system.
• Multiple sclerosis damages the myelin sheath.
• Sensory disorders include cataracts, glaucoma, and hearing loss.
• Neurological damage can impair movement, sensation, and cognition.

Disorders of the male and female reproductive systems.

• Female disorders: endometriosis, PCOS, fibroids, and cancers (cervical, ovarian, breast).
• Male disorders: BPH (enlarged prostate) and prostate/testicular cancer.
• STIs affect both sexes and can impair fertility.
• Hormonal changes drive many reproductive conditions.

Disorders of the kidneys and urinary tract.

• UTIs and kidney stones are common and often painful.
• Acute and chronic kidney disease impair filtering; dialysis may be needed.
• Glomerulonephritis inflames the kidney's filters.
• Kidneys also regulate blood pressure and electrolyte balance.

Psychiatric conditions that affect mood, thought, and behavior.

• Mood disorders include depression and bipolar disorder.
• Anxiety disorders include GAD, panic disorder, and phobias.
• Schizophrenia is a psychotic disorder with hallucinations and delusions.
• These conditions have biological, psychological, and social causes.