Overview

Definition

Hypertension is defined as a BP > 130/80 mm Hg.

• Primary (essential) hypertension is the most common type of hypertension; it has no known cause.
• Secondary hypertension is due to another medical condition or to medications.

Epidemiology

• PrevalencePrevalenceThe total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time.Measures of Disease Frequency depends on the definition of hypertension.
• In 2017, the American College of Cardiology/American Heart AssociationAmerican Heart AssociationA voluntary organization concerned with the prevention and treatment of heart and vascular diseases.Heart Failure (ACC/AHA) lowered thethresholdThresholdMinimum voltage necessary to generate an action potential (an all-or-none response)Skeletal Muscle Contraction for the definition of hypertension, withprevalencePrevalenceThe total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time.Measures of Disease Frequency now 43%–50% in adults. 
• More common in older adults, men, and BlackpatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship

Etiology

Primary hypertension:

The pathogenesis of primary hypertension is poorly understood but is most likely the result of numerous genetic and environmental factors affecting cardiovascular and kidney structure and function. Risk factors:

• MalesexSexThe totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism.Gender Dysphoria
• Advanced age
• Family historyFamily HistoryAdult Health Maintenance
• Race
• SmokingSmokingWillful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand.Interstitial Lung Diseases
• Alcohol consumption
• ObesityObesityObesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors.Obesity
• Diet high insodiumSodiumA member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23.Hyponatremia
• Physical inactivity

Secondary hypertension:

• Medications (oral contraceptives,NSAIDsNSAIDSPrimary vs Secondary Headaches, antidepressants,steroidsSteroidsA group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus.Benign Liver Tumors,stimulantsStimulantsStimulants are used by the general public to increase alertness and energy, decrease fatigue, and promote mental focus. Stimulants have medical uses for individuals with ADHD and sleep disorders, and are also used in combination with analgesics in pain management.Stimulants)
• Illicit drugsIllicit DrugsDrugs that are manufactured, obtained, or sold illegally. They include prescription drugs obtained or sold without prescription and non-prescription drugs. Illicit drugs are widely distributed, tend to be grossly impure and may cause unexpected toxicity.Delirium
• Renal: primary kidney disease, renovascular
• Obstructivesleep apneaSleep apneaRepeated cessation of breathing for > 10 seconds during sleep and results in sleep interruption, fatigue, and daytime sleepiness.Obstructive Sleep Apnea
• Endocrine:pheochromocytomaPheochromocytomaPheochromocytoma is a catecholamine-secreting tumor derived from chromaffin cells. The majority of tumors originate in the adrenal medulla, but they may also arise from sympathetic ganglia (also referred to as paraganglioma). Symptoms are associated with excessive catecholamine production and commonly include hypertension, tachycardia, headache, and sweating.Pheochromocytoma, primary aldosteronism,Cushing syndromeCushing syndromeA condition caused by prolonged exposure to excess levels of cortisol (hydrocortisone) or other glucocorticoids from endogenous or exogenous sources. It is characterized by upper body obesity; osteoporosis; hypertension; diabetes mellitus; hirsutism; amenorrhea; and excess body fluid. Endogenous Cushing syndrome or spontaneous hypercortisolism is divided into two groups, those due to an excess of adrenocorticotropin and those that are acth-independent.Paraneoplastic Syndromes, Graves’ disease
• Coarctation of theaortaAortaThe main trunk of the systemic arteries.Mediastinum and Great Vessels: Anatomy

Classification

Clinical Presentation

General features

• Most often presents with no signs or symptoms
• Can present withheadacheHeadacheThe symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders.Brain Abscess,epistaxisEpistaxisBleeding from the nose.Granulomatosis with Polyangiitis,tinnitusTinnitusA nonspecific symptom of hearing disorder characterized by the sensation of buzzing, ringing, clicking, pulsations, and other noises in the ear. Objective tinnitus refers to noises generated from within the ear or adjacent structures that can be heard by other individuals. The term subjective tinnitus is used when the sound is audible only to the affected individual. Tinnitus may occur as a manifestation of cochlear diseases; vestibulocochlear nerve diseases; intracranial hypertension; craniocerebral trauma; and other conditions.Cranial Nerve Palsies, ordizzinessDizzinessAn imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness.Lateral Medullary Syndrome (Wallenberg Syndrome)

Subtypes

• Isolated office hypertension (“white-coat hypertension“): characterized by measurements ≥ 130/80 mm Hg in the physician’s office, while measurements taken at home and during BP monitoring are normal
• Isolated ambulatory hypertension (“masked hypertension”):
  • Increased systolic BP (≥ 140 mm Hg) with diastolic BP within normal limits (≤ 90 mm Hg)
  • Maskeduncontrolled hypertensionUncontrolled hypertensionAlthough hypertension is defined as a blood pressure of > 130/80 mm Hg, individuals can present with comorbidities of severe asymptomatic or “uncontrolled” hypertension (≥ 180 mm Hg systolic and/or ≥ 120 mm Hg diastolic) that carries with it a significant risk of morbidity and mortality.Uncontrolled Hypertension (MUCH) is diagnosed inpatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship treated for hypertension who are normotensive in the clinic but hypertensive outside.

Diagnosis

Medical history and physical examination

• Prior to diagnosing hypertension, it is important to use an average based on ≥ 2 readings obtained on ≥ 2 occasions.
• Diagnosis of hypertension should be confirmed using out-of-office BP measurement whenever possible.
• In uncommon scenarios, diagnosis can be made if a patient presents with:
  • Severe asymptomatic hypertension (hypertensive urgencyHypertensive urgencyAsymptomatic, or relative asymptomatic, severe hypertension without end-organ damage.Uncontrolled Hypertension): ≥ 180 mm Hg systolic or ≥ 120 mm Hg diastolic
  • An initialscreeningScreeningPreoperative Care BP ≥ 160 mm Hg systolic or ≥ 100 Hg diastolic with known target end-organ damage (e.g., leftventricular hypertrophyVentricular HypertrophyTetralogy of Fallot, hypertensiveretinopathyRetinopathyDegenerative changes to the retina due to hypertension.Alport Syndrome, or hypertensive kidney disease).
• In cases of white-coat hypertension: ambulatory BP monitoring (ABPM) over a period of 24 hours is appropriate.

Laboratory

• HbHbThe oxygen-carrying proteins of erythrocytes. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.Gas Exchange and Hct: may indicateanemiaAnemiaAnemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology.Anemia: Overview and Types due to underlying renal disease
• Creatinine and eGFR levels: to evaluate renal function
• PotassiumPotassiumAn element in the alkali group of metals with an atomic symbol k, atomic number 19, and atomic weight 39. 10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the water-electrolyte balance.Hyperkalemia levels: useful when Conn’s syndrome suspected
• T₃, T₄,thyroid-stimulating hormoneThyroid-stimulating hormoneA glycoprotein hormone secreted by the adenohypophysis. Thyrotropin stimulates thyroid gland by increasing the iodide transport, synthesis and release of thyroid hormones (thyroxine and triiodothyronine).Thyroid Hormones (TSH),aldosteroneAldosteroneA hormone secreted by the adrenal cortex that regulates electrolyte and water balance by increasing the renal retention of sodium and the excretion of potassium.Hyperkalemia, andreninReninA highly specific (leu-leu) endopeptidase that generates angiotensin I from its precursor angiotensinogen, leading to a cascade of reactions which elevate blood pressure and increase sodium retention by the kidney in the renin-angiotensin system.Renal Sodium and Water Regulation: to evaluate for the presence of endocrine hypertension
• UrinalysisUrinalysisExamination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically.Urinary Tract Infections (UTIs) in Children: Microalbuminuria may be an earlyindicatorIndicatorMethods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system.Body Fluid Compartments of renal damage, especially in diabeticpatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship.
• 24-hour urine forcatecholaminesCatecholaminesA general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.Adrenal Hormones/metanephrines: if diastolic BP > 110 mm Hg, levels 2× upperlimitLimitA value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lungInvasive Mechanical Ventilation of normal indicatepheochromocytomaPheochromocytomaPheochromocytoma is a catecholamine-secreting tumor derived from chromaffin cells. The majority of tumors originate in the adrenal medulla, but they may also arise from sympathetic ganglia (also referred to as paraganglioma). Symptoms are associated with excessive catecholamine production and commonly include hypertension, tachycardia, headache, and sweating.Pheochromocytoma

ElectrocardiographyElectrocardiographyRecording of the moment-to-moment electromotive forces of the heart as projected onto various sites on the body’s surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a cathode ray tube display.Electrocardiogram (ECG)

Evaluates for leftventricular hypertrophyVentricular HypertrophyTetralogy of Fallot (LVH): strain pattern often seen with hypertensive heart disease

• Increased R-wave amplitude in V5, V6, I, and aVL
• Increased S-wave amplitude in V1 and V2
• Compensatory ST-segment and T-wave changes

Imaging

• ChestX-rayX-rayPenetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source.Pulmonary Function Tests: useful to determine the presence ofcardiomegalyCardiomegalyEnlargement of the heart, usually indicated by a cardiothoracic ratio above 0. 50. Heart enlargement may involve the right, the left, or both heart ventricles or heart atria. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (heart failure) or several forms of cardiomyopathies.Ebstein’s Anomaly, aortic coarctation
• EchocardiographyEchocardiographyUltrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Tricuspid Valve Atresia (TVA): evaluate for LVH, impaired systolic and/or diastolic function, valvular dysfunction/deformityDeformityExamination of the Upper Limbs
• Renal duplex ultrasound: ifrenovascular hypertensionRenovascular hypertensionHypertension due to renal artery obstruction or compression.Renal Artery Stenosis suspected

Management

Nonpharmacologic measures

• Weight reduction: ideally,BMIBMIAn indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese).Obesity ≤ 25
• Low-sodium diet: ≤ 2300 mg/day
• Mediterranean diet: rich in fruits, vegetables, whole grains, low-fat dairy foods, and olive oil
• SmokingSmokingWillful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand.Interstitial Lung Diseases cessation
• LimitLimitA value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lungInvasive Mechanical Ventilation consumption of alcohol andcoffeeCoffeeA beverage made from ground coffee beans (seeds) infused in hot water. It generally contains caffeine and theophylline unless it is decaffeinated.Constipation to 2 per day.
• RegularRegularInsulin physical activity: 30 minutes 5 days a week

Medical management

Clinical Relevance

Hypertension is a risk factor foratherosclerosisAtherosclerosisAtherosclerosis is a common form of arterial disease in which lipid deposition forms a plaque in the blood vessel walls. Atherosclerosis is an incurable disease, for which there are clearly defined risk factors that often can be reduced through a change in lifestyle and behavior of the patient.Atherosclerosis, which can lead toMIMIMI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms.Myocardial Infarction,ischemic heart diseaseIschemic heart diseaseCoronary heart disease (CHD), or ischemic heart disease, describes a situation in which an inadequate supply of blood to the myocardium exists due to a stenosis of the coronary arteries, typically from atherosclerosis.Coronary Heart Disease,cerebrovascular accidentCerebrovascular accidentAn ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion.Ischemic Stroke, and peripheralischemiaIschemiaA hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation.Ischemic Cell Damage.

Other conditions associated with hypertension include: 

• Polycystic kidney disease (PKD): can be diagnosed in adults and pediatricpatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship. Polycystic kidney disease is an inherited disease that involves bilateralrenal cystsRenal CystsImaging of the Urinary System without dysplasia. There are 2 forms:autosomal recessiveAutosomal recessiveAutosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal recessive diseases are only expressed when 2 copies of the recessive allele are inherited.Autosomal Recessive and Autosomal Dominant Inheritance andautosomal dominantAutosomal dominantAutosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited.Autosomal Recessive and Autosomal Dominant Inheritance.
• Glomerulonephritis: immune-mediatedinflammationInflammationInflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function.Inflammation of the renal glomeruli. Glomerulonephritis can be primary or secondary (due to other diseases).PatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship with glomerulonephritis will present with various symptoms, depending on the pathology, but this disorder is commonly associated with hypertension.
• HyperparathyroidismHyperparathyroidismHyperparathyroidism is a condition associated with elevated blood levels of parathyroid hormone (PTH). Depending on the pathogenesis of this condition, hyperparathyroidism can be defined as primary, secondary or tertiary.Hyperparathyroidism:causes increased peripheral vascularresistanceResistancePhysiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Ventilation: Mechanics of Breathing because of increasedcalciumCalciumA basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Electrolytes levels with resultant elevation in BP.
• HyperaldosteronismHyperaldosteronismHyperaldosteronism is defined as the increased secretion of aldosterone from the zona glomerulosa of the adrenal cortex. Hyperaldosteronism may be primary (resulting from autonomous secretion), or secondary (resulting from physiological secretion due to stimulation of the RAAS). Classically, hyperaldosteronism presents with hypertension, hypokalemia, and metabolic alkalosis.Hyperaldosteronism: patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship present with increased levels ofaldosteroneAldosteroneA hormone secreted by the adrenal cortex that regulates electrolyte and water balance by increasing the renal retention of sodium and the excretion of potassium.Hyperkalemia, which in turn increasessodiumSodiumA member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23.Hyponatremia and water reabsorption, causing hypertension. In theadrenocorticotropic hormoneAdrenocorticotropic hormoneAn anterior pituitary hormone that stimulates the adrenal cortex and its production of corticosteroids. Acth is a 39-amino acid polypeptide of which the n-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotropic activity. Upon further tissue-specific processing, acth can yield alpha-msh and corticotropin-like intermediate lobe peptide (clip).Adrenal Hormones (ACTH)–dependent form,androgensAndrogensAndrogens are naturally occurring steroid hormones responsible for development and maintenance of the male sex characteristics, including penile, scrotal, and clitoral growth, development of sexual hair, deepening of the voice, and musculoskeletal growth.Androgens and Antiandrogens may also be increased, and women can experiencehirsutismHirsutismA condition observed in women and children when there is excess coarse body hair of an adult male distribution pattern, such as facial and chest areas. It is the result of elevated androgens from the ovaries, the adrenal glands, or exogenous sources. The concept does not include hypertrichosis, which is an androgen-independent excessive hair growth.Polycystic Ovarian Syndrome and menstrual disruptions.

References

1. Basile, J., Block, J. (2021). Overview of hypertension in adults. UpToDate. Retrieved March 18, 2021, from https://www.uptodate.com/contents/overview-of-hypertension-in-adults
2. Whelton, P.K., Carey, R.M. et al. (2017). ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. https://www.jacc.org/doi/full/10.1016/j.jacc.2017.11.006?_ga=2.178229602.677038771.1616197579-1081973158.1616197579
3. Unger, T., Borghi, C., Charchar, F., et al. (2020.) International Society of Hypertension Global Hypertension Practice Guidelines. Hypertension 75:1334–1357.