High Blood Pressure (Hypertension): Symptoms, Causes and Effective Treatment

What Is High Blood Pressure (Hypertension)?

Hello, I am Dr. Emre Geçer. High blood pressure — known in medicine as hypertension — is the condition in which the pressure that blood exerts on the walls of the arteries is persistently higher than normal. Blood pressure is expressed as two values: systolic pressure (the upper value, generated when the heart contracts) and diastolic pressure (the lower value, when the heart relaxes). It is measured in millimeters of mercury (mmHg).

Hypertension is usually silent — it can damage target organs for years without producing any obvious symptoms. This is why it is called the "silent killer." An estimated 1.4 billion people worldwide are affected by hypertension, and a large proportion are unaware of their condition.

Blood Pressure Classification (ACC/AHA 2017 Guideline)

According to the 2017 update of the American College of Cardiology and the American Heart Association, blood pressure is classified as:

• Normal: Systolic <120 mmHg and diastolic <80 mmHg
• Elevated: Systolic 120–129 mmHg and diastolic <80 mmHg
• Stage 1 hypertension: Systolic 130–139 mmHg or diastolic 80–89 mmHg
• Stage 2 hypertension: Systolic ≥140 mmHg or diastolic ≥90 mmHg
• Hypertensive crisis: Systolic >180 mmHg and/or diastolic >120 mmHg

Important note: Diagnosis should be based not on a single measurement but on confirmation of elevated values across at least two separate measurements at different times. Home blood pressure monitoring (HBPM) and 24-hour ambulatory blood pressure monitoring (ABPM) provide more reliable results.

Causes of Hypertension

Primary (Essential) Hypertension — 90–95%

Primary hypertension accounts for the vast majority of cases and has no single identifiable cause. It develops from the interaction of genetic predisposition, environmental factors and lifestyle. Major risk factors include:

• Genetic predisposition: A family history of hypertension raises the risk 2–3-fold.
• Excess salt (sodium) intake: Daily salt consumption over 5 grams.
• Obesity: Hypertension risk rises markedly as body mass index (BMI) increases.
• Physical inactivity: Sedentary lifestyle.
• Excessive alcohol intake: More than 2 standard drinks per day for men, more than 1 per day for women.
• Stress: Chronic stress raises blood pressure via sympathetic nervous system activation.
• Advancing age: Arterial stiffness (arteriosclerosis) increases with age.
• Inadequate potassium intake: Potassium counterbalances the blood-pressure-raising effect of sodium.

Secondary Hypertension — 5–10%

Secondary hypertension has an identifiable underlying cause, and treating that cause can resolve the hypertension. It should especially be investigated in young patients (<30), resistant hypertension or sudden-onset cases:

• Renal parenchymal disease: Chronic kidney disease, glomerulonephritis.
• Renovascular hypertension: Renal artery stenosis (atherosclerosis or fibromuscular dysplasia).
• Primary aldosteronism (Conn syndrome): Excess aldosterone secretion from the adrenal gland.
• Pheochromocytoma: Excess catecholamine secretion from the adrenal medulla — the paroxysmal triad of hypertension, headache, sweating and palpitations.
• Cushing syndrome: Excess cortisol.
• Coarctation of the aorta: Congenital narrowing of the aorta — high blood pressure in the upper extremities and low blood pressure in the lower extremities.
• Obstructive sleep apnea: An increasingly recognized and important secondary cause.
• Thyroid disorders: Hyperthyroidism and hypothyroidism.
• Medications: Oral contraceptives, NSAIDs, decongestants, corticosteroids, cyclosporine.

Symptoms of Hypertension

Hypertension is usually asymptomatic (gives no symptoms). This is the most dangerous aspect of the disease because many people spend years unaware that their blood pressure is high. However, some patients may experience the following:

• Headache in the back of the head (occipital), especially on waking
• Dizziness and lightheadedness
• Blurred vision or double vision
• Ringing in the ears (tinnitus)
• Shortness of breath (especially with exertion)
• Nosebleed (epistaxis)
• Chest pain or palpitations
• Weakness and fatigue

Critical warning: These symptoms typically appear in advanced hypertension or during acute spikes. The absence of symptoms does not mean the disease is not present. For this reason, regular blood pressure checks are recommended from the age of 18.

White-Coat and Masked Hypertension

White-Coat Hypertension

Blood pressure measured in the doctor's office is high, but readings at home and during daily life are normal. The anxiety and stress of the clinical setting activate the sympathetic nervous system and cause transient blood pressure elevation. Prevalence is between 15% and 30%. Although cardiovascular risk in these patients is slightly higher than in true normotensives, it is lower than in patients with sustained hypertension. The gold standard for diagnosis is 24-hour ABPM or regular home BP monitoring (HBPM).

Masked Hypertension

This is the opposite situation: office readings are normal, but home measurements or ABPM reveal high blood pressure. This is more dangerous than white-coat hypertension because patients are considered normotensive and remain untreated. Masked hypertension carries a target-organ-damage risk similar to that of sustained hypertension.

Target-Organ Damage — How High Blood Pressure Affects the Body

Uncontrolled hypertension gradually damages vital organs:

Effects on the Heart

• Left ventricular hypertrophy (LVH): The heart muscle thickens against the increased pressure; sets the stage for diastolic dysfunction and heart failure.
• Coronary artery disease: Atherosclerosis accelerates, raising the risk of angina pectoris and myocardial infarction (heart attack).
• Heart failure: Both systolic and diastolic heart failure can develop.
• Atrial fibrillation: LVH and left atrial enlargement increase the risk of arrhythmia.

Effects on the Brain

• Ischemic stroke: Occlusion of cerebral vessels — hypertension is the most important modifiable risk factor.
• Hemorrhagic stroke: Intracerebral hemorrhage — especially in uncontrolled hypertension.
• Hypertensive encephalopathy: Cerebral edema in acute, severe hypertension.
• Vascular dementia: Chronic hypertension is linked to small-vessel disease and cognitive decline.

Effects on the Kidneys

• Hypertensive nephropathy: Damage to renal blood vessels and falling glomerular filtration rate.
• Proteinuria / albuminuria: Protein loss in the urine — an early sign of kidney damage.
• Chronic kidney disease and end-stage renal failure: Together with diabetes, hypertension is one of the two most common causes of end-stage renal disease.

Effects on the Eyes

• Hypertensive retinopathy: Narrowing of retinal vessels, hemorrhages, exudates, papilledema.
• Retinal vein/artery occlusion: Sudden loss of vision.

Lifestyle Changes — The First and Most Important Step

Lifestyle modifications form the foundation of hypertension treatment. They may be sufficient on their own in stage 1 hypertension; in patients on medication, they enhance drug efficacy and reduce the required dose.

1. The DASH Diet

DASH (Dietary Approaches to Stop Hypertension) is the dietary pattern with the strongest evidence base for hypertension. Its core principles are:

• Plenty of fruit and vegetables (8–10 servings per day)
• Whole grains and low-fat dairy products
• Lean white meat, fish, legumes, nuts
• Limiting saturated fat, red meat, and sugary food and drinks

On its own, the DASH diet can lower systolic blood pressure by 8–14 mmHg — an effect comparable to that of some medications.

2. Sodium (Salt) Restriction

Daily sodium intake should be reduced to below 2.3 grams (about 1 teaspoon of salt); the ideal target is 1.5 grams/day. Average salt consumption in Turkey is around 15–18 grams per day, which is 3–4 times the recommended amount. Sodium restriction can lower systolic blood pressure by 5–6 mmHg. Processed foods, pickled products, canned goods and bread are major hidden sources of salt.

3. Regular Physical Activity

At least 150 minutes per week of moderate-intensity aerobic exercise (brisk walking, swimming, cycling) or 75 minutes of high-intensity activity is recommended. Regular exercise reduces systolic blood pressure by an average of 5–8 mmHg. Resistance training such as weight lifting is also beneficial, but heavy lifting should be discussed with a doctor first.

4. Weight Loss

Every 1 kg of weight loss lowers systolic blood pressure by approximately 1 mmHg. Waist circumference targets: <102 cm for men, <88 cm for women. Even a 5–10% weight loss in obese individuals has a noticeable effect on blood pressure.

5. Alcohol Restriction

Men should not exceed 2 standard drinks per day, and women should not exceed 1. Excessive alcohol both directly raises blood pressure and reduces the effectiveness of antihypertensive medications.

6. Quitting Smoking

Smoking is not a direct, continuous cause of hypertension, but every cigarette produces a transient rise in blood pressure and — more importantly — dramatically increases cardiovascular risk. In a hypertensive patient, smoking multiplies the risk of heart attack and stroke.

Drug Therapy

Drug therapy is started when target blood pressure is not reached despite lifestyle changes or when cardiovascular risk is high. The main classes of antihypertensive drugs are:

1. ACE Inhibitors (ACEi)

Drugs such as enalapril, ramipril, lisinopril and perindopril. They act by blocking the renin–angiotensin–aldosterone system (RAAS). They are particularly preferred in diabetic nephropathy and heart failure. The most common side effect is a dry cough (5–20%). They are absolutely contraindicated in pregnancy (teratogenic).

2. Angiotensin Receptor Blockers (ARBs)

Drugs such as losartan, valsartan, irbesartan and telmisartan. They share a similar mechanism with ACE inhibitors but produce much less cough. They are preferred as alternatives in patients who develop ACE-inhibitor-related cough. They have the same contraindications as ACE inhibitors.

3. Calcium Channel Blockers (CCBs)

Drugs such as amlodipine, nifedipine, diltiazem and verapamil. The dihydropyridine group (amlodipine, nifedipine) relaxes vascular smooth muscle; the non-dihydropyridine group (diltiazem, verapamil) also slows heart rate. They are effective in older adults and isolated systolic hypertension. Ankle edema is the most common side effect.

4. Thiazide Diuretics

Drugs such as hydrochlorothiazide, chlorthalidone and indapamide. They act by increasing renal excretion of sodium and water. They are cost-effective and a long-established and effective group. Electrolyte disturbances (hypokalemia, hyponatremia) and metabolic effects (elevated uric acid, glucose intolerance) should be monitored.

5. Other Groups

• Beta blockers: Atenolol, metoprolol, bisoprolol — preferred when heart failure, coronary artery disease or tachycardia is also present.
• Alpha blockers: Doxazosin — an add-on agent in resistant hypertension; useful when prostate hypertrophy coexists.
• Mineralocorticoid receptor antagonists: Spironolactone — strong evidence as a fourth-line drug in resistant hypertension.
• Direct renin inhibitors: Aliskiren.

Treatment usually starts with a single drug, and combination therapy is added if needed. In stage 2 hypertension, a two-drug combination may be preferred from the outset. Treatment should be individualized, taking into account the patient's comorbidities, age and tolerability.

Hypertensive Crisis: An Emergency

Systolic blood pressure >180 and/or diastolic >120 mmHg is defined as a hypertensive crisis. It is divided into two subgroups:

Hypertensive Emergency

Severely elevated blood pressure with target-organ damage. It includes acute stroke, acute myocardial infarction, acute heart failure (pulmonary edema), aortic dissection, hypertensive encephalopathy and eclampsia. It requires intravenous antihypertensive therapy in intensive care. Blood pressure should not be lowered by more than 25% in the first hour, and target values should be reached gradually over the next 24–48 hours.

Hypertensive Urgency

Blood pressure is markedly elevated but there is no evidence of target-organ damage. Patients may have severe headache or nosebleed. The aim is gradual reduction over hours to days using oral antihypertensive drugs. Sudden lowering in panic can reduce cerebral or coronary perfusion and cause harm.

When Should You See a Doctor?

• If home measurements repeatedly show systolic ≥130 or diastolic ≥80 mmHg
• Sudden severe headache, blurred vision, chest pain or shortness of breath
• Uncontrolled nosebleed
• Blood pressure not at target despite taking antihypertensive medication
• Bothersome side effects (cough, dizziness, ankle swelling) — do not stop the medication on your own; talk to your doctor
• If you are planning a pregnancy or have become pregnant — some antihypertensive drugs are contraindicated in pregnancy
• If blood pressure is over 180/120 mmHg and there is any sign of organ damage, go to the emergency department

Conclusion

Hypertension is a disease that can be controlled with early diagnosis and consistent treatment. Its silent course does not make it less dangerous — on the contrary, every year it goes unnoticed adds irreversible damage to the heart, brain, kidneys and eyes. Lifestyle changes are an essential foundation of treatment and, combined with medication, often produce dramatic results. Measure your blood pressure regularly, eat healthily, stay active and follow your doctor's recommended treatment plan.

Wishing you healthy days.
Dr. Emre Geçer

References

• Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 12th Edition — Chapters: Systemic Hypertension
• Harrison's Principles of Internal Medicine, 22nd Edition — Chapter: Hypertensive Vascular Disease
• Whelton PK, et al. 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Journal of the American College of Cardiology, 2018
• JNC 8 — Evidence-Based Guideline for the Management of High Blood Pressure in Adults (JAMA, 2014)