A Deep Dive into Hypertension: A Comprehensive Analysis from Basic Concepts and Common Symptoms to Health Hazards and Essential Examinations

Understanding Hypertension and Related Concepts of Blood Pressure: What is Blood Pressure? Blood pressure is the lateral pressure exerted by blood on the walls of blood vessels per unit area as blood flows through them. It is the driving force propelling blood flow within the vessels. The pressure exerted by blood on arteries is called arterial pressure, the pressure on capillaries is called capillary pressure, and the pressure on veins is called venous pressure. Blood pressure varies between different types of blood vessels, and even within arteries, the blood pressure differs between large arteries and peripheral arterioles. Systolic and Diastolic Blood Pressure: Systolic pressure is the pressure exerted by blood on blood vessels when they constrict, also known as high pressure; diastolic pressure is the pressure exerted by blood on blood vessels when they dilate, also known as low pressure. When measuring blood pressure, the doctor will give you two values. Generally, the larger number is your systolic pressure, and the smaller number is your diastolic pressure. Under normal circumstances, a person's systolic blood pressure is around 120 mmHg (16 kPa), and the diastolic blood pressure is around 80 mmHg, with slight individual variations. When blood pressure reaches 130–139/85–89 mmHg, it is considered "borderline hypertension." At this point, vigilance is necessary, and obese individuals should lose weight promptly. If blood pressure is ≥140/90 mmHg on three separate occasions, not on the same day, hypertension should be suspected. Adult blood pressure classifications: Ideal blood pressure: Systolic pressure (mmHg): <120; Conditions: and ; Diastolic pressure (mmHg): <80. Normal blood pressure: Systolic pressure (mmHg): <130; Conditions: and ; Diastolic pressure (mmHg): <85. High-normal blood pressure: Systolic pressure (mmHg): 130–139; Conditions: and/or ; Diastolic pressure (mmHg): 85–89. Mild hypertension: Systolic pressure (mmHg): 140–159; Conditions: and/or ; Diastolic pressure (mmHg): 90–99. Classification: Moderate hypertension; Systolic blood pressure (mmHg): 160–179; Conditions: and/or; Diastolic blood pressure (mmHg): 100–109. Classification: Severe hypertension; Systolic blood pressure (mmHg): ≥180; Conditions: and/or; Diastolic blood pressure (mmHg): ≥110. Classification: Isolated systolic hypertension; Systolic blood pressure (mmHg): ≥140; Conditions: and; Diastolic blood pressure (mmHg): <90.

In the early stages of hypertension, most patients do not experience obvious symptoms. Only after years of hypertension may symptoms such as tinnitus, hearing loss, palpitations, and dizziness appear. Specifically, these symptoms mainly manifest in the following ways: Numbness in the limbs: This usually improves with treatment. However, if the pain or numbness occurs in a fixed location and is accompanied by convulsions or spasms, there is a risk of stroke, and immediate medical attention is necessary. Headache: Headaches often occur in the temples or back of the head in hypertensive patients, and are usually a regular throbbing or persistent burning pain, sometimes even causing excruciating pain. The headache worsens with strenuous exercise or fatigue. Dizziness and vertigo: Dizziness is the most common symptom of hypertension. It occurs when suddenly standing up after squatting, and objects may appear to "flash." Mental confusion and forgetfulness: These symptoms worsen as hypertension progresses. Patients experience forgetfulness and difficulty concentrating; in severe cases, it can even lead to Alzheimer's disease. Tinnitus can be perceived as a cicada's chirping or other sounds even in a very quiet environment. If it persists for a long time, it's best to go to the hospital to find out the cause. Anxiety, insomnia, and hypertension often cause patients to put themselves under a lot of mental stress, leading to anxiety, tension, palpitations, insomnia, or suddenly waking up from dreams. They may also become inexplicably angry and lash out at others.

The dangers of hypertension include: ◎ Cerebral hemorrhage and cerebral infarction: Hypertension easily causes arteriosclerosis in capillaries, and cerebral arteries also develop arteriosclerosis due to the accumulation of cholesterol and triglycerides. When large and small blood vessels (arteries) in the brain harden, they are prone to rupture, leading to cerebral hemorrhage. ◎ Cerebral infarction: When blood pressure rises, blood flow is obstructed. Brain cells, deprived of necessary oxygen and nutrients, die, affecting normal brain function. ◎ Kidney disease: Long-term hypertension causes arteriosclerosis of renal arterioles, leading to insufficient blood supply to the kidneys and kidney failure. Furthermore, with declining kidney function, harmful substances cannot be excreted from the body in time, easily inducing uremia. ◎ Angina pectoris: Angina pectoris is a disease caused by temporary obstruction of blood flow to the heart, resulting in a lack of oxygen and nutrients. Angina pectoris is a representative of ischemic heart disease, primarily caused by arteriosclerosis due to hypertension. Studies on myocardial infarction have found that the incidence of myocardial infarction in hypertensive patients is twice as high as in normal individuals. Hypertension also increases the risk of acute myocardial infarction and raises both short-term and long-term mortality rates after infarction. This is because hypertension increases the incidence of serious complications associated with myocardial infarction; for example, 53% of patients with cardiac rupture during acute myocardial infarction also have hypertension. Myocardial infarction accompanied by chronic heart failure is also common in individuals with pre-existing hypertension. Hypertension can cause retinal hemorrhage, as it easily leads to spasm and hardening of the retinal arterioles. A sharp rise in blood pressure can also cause retinal hemorrhage. Hypertension's most direct impact on the heart is cardiac hypertrophy. Cardiac hypertrophy refers to the thickening of the heart muscle and an overall enlargement of the heart. When the myocardium becomes hypertrophic, the coronary arteries and capillaries supplying oxygen and nutrients to the myocardium do not grow accordingly, resulting in a state of hypoxia and malnutrition (ischemia). Furthermore, when the myocardium is hypertrophic, the intercellular fibrous material (collagen fibers) increases, causing the myocardium to lose elasticity and harden, reducing the heart's pumping function. Due to the aforementioned dual damage, the heart will enter a state of chronic ischemia, leading to symptoms such as shortness of breath, difficulty breathing, palpitations, and arrhythmia. If the symptoms are severe, it can even cause heart failure. Hypertension, which causes atherosclerosis, increases the burden on and damages the arterial walls, thus leading to atherosclerosis.

Essential tests for hypertension include: Electrocardiogram (ECG): Long-term hypertension increases the burden on the heart, easily leading to myocardial hypertrophy to resist rising blood pressure. This causes changes in heartbeat, which are reflected in the ECG. Therefore, an ECG can determine if there are heart problems in hypertensive patients. Blood tests: When kidney failure occurs in hypertensive patients, blood potassium levels rise. In cases of renal artery sclerosis due to hypertension, blood uric acid levels increase. Many hypertensive patients also have high blood viscosity. Therefore, blood tests are very helpful in diagnosing hypertension syndromes such as atherosclerosis, kidney disease, and heart disease. Fundus examination: Long-term hypertension can cause vascular lesions in the retina, affecting vision and, in severe cases, even leading to retinal hemorrhage. Generally, narrowing or slight hardening of the small arteries in the fundus may indicate mid-stage hypertension; significant hardening of the small arteries in the fundus may indicate late-stage hypertension; and the presence of optic disc edema may indicate malignant hypertension. Urine tests: As hypertension progresses, it can cause dysfunction of the renal arterioles, leading to kidney disease. Urine tests can clearly show the amount of protein and sugar in the urine, thus helping to diagnose the condition. Echocardiography reveals left ventricular enlargement in patients with hypertension and heart disease. In cases of total heart failure, both ventricles may enlarge, accompanied by signs of pulmonary congestion. All of these can be detected by echocardiography. Compared to electrocardiograms and chest X-rays, echocardiography is the most sensitive and reliable method for diagnosing left ventricular hypertrophy. Chest X-rays can reveal the shape of the heart and the diameter of the aorta, thus assessing the impact of hypertension on the arteries and heart.