Hypertension
What is Hypertension?
Hypertension refers to a condition where there is a sustained increase in systemic arterial blood pressure. According to the 2014 clinical guidelines, hypertension is diagnosed when systolic blood pressure is at or above 140 mmHg or diastolic blood pressure is at or above 90 mmHg. However, the 2017 update revised these thresholds to lower values, with systolic pressure at 130 mmHg or more and diastolic pressure at 80 mmHg or more. This change reflects emerging evidence linking cardiovascular risk to lower blood pressure levels than previously recognized (American College of Cardiology/American Heart Association Task Force, 2017; James et al., 2014).
What is the Epidemiology of Hypertension?
Hypertension is the most common primary diagnosis in the United States, affecting a large portion of the adult population. Approximately 95% of cases are classified as primary or essential hypertension, where no definitive cause is identified. Secondary hypertension, which accounts for about 5% of cases, stems from identifiable underlying conditions, such as renal disease (Mayo Clinic, 2025).
What Types of Hypertension Exist?
| Type | Characteristics | Cause | Outcome |
|---|---|---|---|
| Primary (Essential) | No specific cause; linked to genetic and environmental factors | Genetic and environmental interactions | Causes increased vascular tone and blood volume, resulting in sustained high blood pressure |
| Secondary | Caused by specific diseases (e.g., kidney disorders) | Increased peripheral resistance or cardiac output | May be reversible with early treatment |
What Are the Risk Factors for Primary Hypertension?
Risk factors for primary hypertension can be grouped into three categories:
Nonmodifiable: Age, ethnicity, family history, and genetic predisposition.
Socioeconomic and Behavioral: Low educational attainment, socioeconomic status, tobacco use, psychological stress, and conditions like obstructive sleep apnea.
Dietary and Metabolic: High intake of sodium and fats, obesity, and glucose intolerance.
These factors also contribute significantly to the overall risk for cardiovascular disease (American College of Cardiology/American Heart Association Task Force, 2017).
What is the Pathophysiology of Hypertension?
Hypertension arises from increased cardiac output, increased total peripheral resistance, or a combination of both. Chronic elevated blood pressure damages vital organs over time, contributing to complications in the heart, kidneys, brain, and vasculature.
What are the Clinical Manifestations of Hypertension?
Often referred to as the “silent disease,” hypertension initially presents without symptoms. Signs typically develop only after target organs have been affected, such as coronary artery disease, heart failure, renal insufficiency, stroke, cognitive decline, visual disturbances, edema, or vascular occlusions.
How is Hypertension Diagnosed?
A diagnosis requires measuring blood pressure on at least two separate visits, averaging two readings spaced two minutes apart. Accurate technique is essential: the patient should be seated comfortably with the arm at heart level, rested, and should avoid caffeine or smoking prior to measurement.
How is Hypertension Managed?
Management focuses on lifestyle modifications like dietary changes, regular physical activity, and stress reduction. Pharmacological treatment is prescribed based on hypertension severity and follows current clinical guidelines (James et al., 2014; Mayo Clinic, 2025).
Metabolic Syndrome
What is Metabolic Syndrome?
Metabolic syndrome describes a group of interconnected metabolic abnormalities that significantly increase the risk for type 2 diabetes and cardiovascular diseases.
What are the Components of Metabolic Syndrome?
| Component | Description |
|---|---|
| Central (abdominal) obesity | Excess fat accumulation around the abdomen |
| Dyslipidemia | Abnormal lipid levels, including elevated triglycerides and low HDL cholesterol |
| Prehypertension | Elevated blood pressure, but not yet in hypertensive range |
| Elevated fasting blood glucose | Higher-than-normal blood sugar levels, indicating insulin resistance |
What is the Epidemiology of Metabolic Syndrome?
Metabolic syndrome may begin during childhood and is prevalent among sedentary adults and overweight youth. Early identification and intervention are crucial to prevent progression to more serious health conditions (National Heart, Lung, and Blood Institute, 2025).
How is Metabolic Syndrome Managed?
Management relies heavily on early screening and lifestyle modifications aimed at weight reduction, healthy eating, and increasing physical activity levels.
Deep Vein Thrombosis (DVT)
What is Deep Vein Thrombosis?
DVT is the formation of a thrombus within a deep vein, typically in the lower limbs, which remains attached to the vessel wall.
What are the Risk Factors for DVT?
| Risk Factor |
|---|
| Hospitalization |
| Trauma |
| Orthopedic surgery |
| Age over 60 |
| Pregnancy |
| Malignancy |
| Inherited thrombophilias (e.g., Factor V Leiden) |
What is the Pathophysiology of DVT?
DVT develops due to a combination of venous stasis, endothelial injury, and a hypercoagulable state—collectively termed Virchow’s triad. Thrombus formation often occurs near venous valves.
What are the Clinical Manifestations of DVT?
DVT can be asymptomatic but may present with symptoms such as unilateral leg pain, swelling, superficial vein dilation, or skin discoloration.
How is DVT Diagnosed?
Initial screening often involves a D-dimer blood test, which is sensitive but lacks specificity. Definitive diagnosis is achieved through compression Doppler ultrasound imaging.
What are the Prevention and Treatment Strategies for DVT?
Preventive measures include early mobilization and the use of compression devices for high-risk individuals. Treatment primarily involves anticoagulation therapy, tailored to the patient’s specific risk factors (Kahn et al., 2024).
Angina Pectoris
What is Angina Pectoris?
Angina pectoris is chest pain caused by myocardial ischemia, resulting from inadequate blood supply to the heart muscle.
What Types of Angina Exist?
| Type | Description | Clinical Features | Treatment |
|---|---|---|---|
| Stable Angina | Predictable, occurs with exertion | Relieved by rest; no myocardial necrosis | Lifestyle changes, nitrates |
| Unstable Angina | Occurs at rest or more frequently | Associated with plaque rupture; risk of myocardial infarction (MI) | Urgent medical care |
| Prinzmetal (Variant) Angina | Caused by coronary artery spasm | Occurs at rest, often at night | Calcium channel blockers, nitrates |
Heart Failure
What is Heart Failure?
Heart failure is a syndrome where the heart cannot pump sufficiently to meet the body’s needs or maintain adequate filling pressures.
What are the Types of Heart Failure?
| Type | Features |
|---|---|
| Left-sided Systolic (HFrEF) | Ejection fraction (EF) less than 40%, impaired myocardial contraction |
| Left-sided Diastolic (HFpEF) | Normal EF but impaired ventricular relaxation |
| Right-sided Heart Failure | Usually caused by left-sided failure, resulting in systemic venous congestion |
Cardiogenic Shock
What is Cardiogenic Shock?
This is a critical condition where the heart fails to pump enough blood despite normal filling pressures, leading to inadequate tissue perfusion.
What are the Clinical Features of Cardiogenic Shock?
Patients often experience hypotension, rapid heart rate (tachycardia), shortness of breath (dyspnea), and reduced perfusion to organs, potentially causing multi-organ failure.
Hypoplastic Left Heart Syndrome (HLHS)
What is HLHS?
HLHS is a congenital heart defect characterized by underdevelopment of the left heart structures, resulting in insufficient systemic blood flow.
How Does HLHS Present?
Newborns may appear normal initially but rapidly deteriorate when the ductus arteriosus closes after birth.
How is HLHS Managed?
Management includes prostaglandin infusion to maintain ductus arteriosus patency, followed by staged surgical procedures—Norwood, Glenn, and Fontan—to palliate circulation (Mayo Clinic, 2025).
Hematologic Disorders
What are Some Key Hematologic Disorders?
| Disorder | Description | Key Features |
|---|---|---|
| Sickle Cell Disease | Autosomal recessive disorder causing sickled red cells | Vaso-occlusion and chronic organ damage |
| Disseminated Intravascular Coagulation (DIC) | Systemic coagulation activation with simultaneous clotting and bleeding | Severe thrombosis and hemorrhage |
| Pernicious Anemia | Vitamin B12 deficiency due to intrinsic factor loss | Megaloblastic anemia, neurological symptoms |
| Iron Deficiency Anemia | Most common anemia worldwide caused by blood loss or poor iron intake | Microcytic, hypochromic RBCs |
What Are Leukemias?
| Type | Characteristics | Common Demographics |
|---|---|---|
| Acute Leukemias | Proliferation of immature blasts | Acute lymphoblastic leukemia (ALL) in children; acute myeloid leukemia (AML) in adults |
| Chronic Leukemias | Involvement of more mature cells | Chronic lymphocytic leukemia (CLL) characterized by smudge cells and immune dysfunction |
Myocardial Infarction
What is a Myocardial Infarction?
Myocardial infarction (MI) occurs when prolonged ischemia causes myocardial cell death.
What are the Types of MI?
| Type | Description |
|---|---|
| STEMI | Transmural infarction affecting the entire thickness of the myocardium |
| NSTEMI | Subendocardial infarction affecting only the inner layers |
How is MI Diagnosed?
Diagnosis is based on elevated cardiac troponin levels and characteristic changes seen on the electrocardiogram (ECG).
What is the Management of MI?
Treatment requires urgent reperfusion using percutaneous coronary intervention (PCI) or thrombolytic therapy, combined with antiplatelet and anticoagulant medications. Long-term management includes modification of cardiovascular risk factors (American College of Cardiology/American Heart Association Task Force, 2017).
Neurologic Disorders
What are Important Concepts in Neurologic Disorders?
Cerebral perfusion pressure (CPP) is calculated by subtracting intracranial pressure (ICP) from mean arterial pressure (MAP). Increased ICP can reduce brain perfusion, causing brain injury. Damage to the brainstem affects consciousness and vital autonomic functions.
What Are Major Neurologic Conditions?
Critical neurologic disorders include locked-in syndrome, subarachnoid hemorrhage, spinal cord injury with autonomic dysreflexia, cerebral edema and herniation, seizures, epilepsy, delirium, and dementia.
References
American College of Cardiology/American Heart Association Task Force. (2017). 2017 ACC/AHA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. Journal of the American College of Cardiology, 71(19), e127-e248.
James, P. A., Oparil, S., Carter, B. L., Cushman, W. C., Dennison-Himmelfarb, C., Handler, J., … & Ortiz, E. (2014). 2014 evidence-based guideline for the management of high blood pressure in adults. JAMA, 311(5), 507-520.
Mayo Clinic. (2025). Hypertension (high blood pressure). https://www.mayoclinic.org/diseases-conditions/high-blood-pressure
National Heart, Lung, and Blood Institute. (2025). What is metabolic syndrome? https://www.nhlbi.nih.gov/health-topics/metabolic-syndrome
Kahn, S. R., et al. (2024). Deep vein thrombosis and pulmonary embolism. The Lancet, 393(10172), 1839-1852.