Overview of Common Diseases
(A concise, organized guide for quick reference and deeper study)
1. Infectious Diseases
| Category |
Representative Conditions |
Causative Agent |
Main Transmission |
Key Clinical Features |
Primary Prevention |
| Respiratory |
Influenza, COVID‑19, Tuberculosis |
Viruses (influenza, SARS‑CoV‑2) / Mycobacterium tuberculosis |
Droplet, aerosol, close contact |
Fever, cough, dyspnea, myalgia; TB → chronic cough, night sweats |
Vaccination, masks, ventilation, BCG (TB) |
| Gastrointestinal |
Salmonellosis, Cholera, Hepatitis A |
Bacteria (Salmonella, Vibrio cholerae) / Virus (HAV) |
Fecal‑oral, contaminated food/water |
Diarrhea, abdominal cramps, vomiting; hepatitis → jaundice |
Safe food handling, water treatment, HAV vaccine |
| Vector‑borne |
Dengue, Malaria, Lyme disease |
Dengue virus / Plasmodium spp. / Borrelia burgdorferi |
Mosquito bite, tick bite |
High fever, rash, arthralgia (dengue); cyclical fevers, anemia (malaria); erythema migrans (Lyme) |
Insect repellent, bed nets, vector control, tick checks |
| Sexually Transmitted |
HIV, Syphilis, Chlamydia |
Virus (HIV) / Bacteria (Treponema pallidum, Chlamydia trachomatis) |
Sexual contact, blood |
Chronic immunosuppression (HIV); chancre, rash (syphilis); urethritis (chlamydia) |
Safe sex, condom use, regular screening, PrEP (HIV) |
2. Non‑Communicable Diseases (NCDs)
2.1 Cardiovascular Diseases (CVD)
| Condition |
Pathophysiology |
Major Risk Factors |
Typical Presentation |
First‑line Management |
| Ischemic Heart Disease (IHD) |
Atherosclerotic plaque → myocardial ischemia |
Hypertension, dyslipidemia, smoking, diabetes, sedentary lifestyle |
Chest pressure, radiating pain, dyspnea, diaphoresis |
Aspirin, β‑blocker, statin, revascularization (PCI/CABG) |
| Stroke (ischemic & hemorrhagic) |
Cerebral artery occlusion or rupture |
Hypertension, atrial fibrillation, smoking, hyperlipidemia |
Sudden focal neurological deficit, speech changes |
Thrombolysis (ischemic), blood pressure control, neurosurgery (hemorrhagic) |
| Heart Failure |
Impaired ventricular filling or ejection |
Ischemic heart disease, hypertension, valvular disease |
Dyspnea, edema, fatigue, orthopnea |
ACE‑I/ARB, β‑blocker, diuretics, device therapy (CRT/ICD) |
2.2 Metabolic Disorders
| Condition |
Core Mechanism |
Diagnostic Criteria |
Common Complications |
Lifestyle/Pharmacologic Treatment |
| Type 2 Diabetes Mellitus |
Insulin resistance + β‑cell dysfunction |
FPG ≥126 mg/dL, 2‑hr OGTT ≥200 mg/dL, HbA1c ≥6.5 % |
Retinopathy, nephropathy, neuropathy, CVD |
Diet, exercise, metformin → GLP‑1 RA/SGL |