Hypertension Classification, Diagnosis, and Warnings: Recognizing the "Hidden Killer" Threatening Cardiovascular, Cerebrovascular, and Renal Health

Classification and Diagnosis of Hypertension

Hypertension is classified into two categories: primary hypertension and secondary hypertension. Primary hypertension refers to hypertension for which no identifiable cause can be found after ruling out any known diseases or causes of elevated blood pressure. Secondary hypertension, also called symptomatic hypertension, is hypertension for which a definite cause can be found. In this case, hypertension is merely a clinical symptom of the primary disease. Generally speaking, secondary hypertension is relatively easy to treat because the cause can be identified, requiring only treatment of the underlying condition. Because the causes of primary hypertension are complex, lifelong treatment and management are required. The goal is to control secondary damage to vital organs such as the heart, brain, and kidneys caused by hypertension. From September 29th to October 1st, 1998, the 7th World Health Organization/International Hypertension League Hypertension Congress was held in Japan. At this conference, new diagnostic criteria for hypertension were established. The definition is: In the absence of antihypertensive medication, a systolic blood pressure greater than or equal to 140 mmHg and a diastolic blood pressure greater than or equal to 90 mmHg; Even if a person has a history of hypertension and is currently using antihypertensive medication, and their current blood pressure does not reach the above levels, they should still be diagnosed with hypertension.

Definition and Classification of Blood Pressure Levels

Normal Blood Pressure: Systolic pressure <120, Diastolic pressure <80
High-Normal: Systolic pressure 120~139, Diastolic pressure 80~89
Hypertension: Systolic pressure ≥140, Diastolic pressure ≥90
Grade 1 Hypertension (Mild): Systolic pressure 140~159, Diastolic pressure 90~99
Grade 2 Hypertension (Moderate): Systolic pressure 160~179, Diastolic pressure 100~109
Grade 3 Hypertension (Severe): Systolic pressure ≥180, Diastolic pressure ≥110
Isolated Systolic Hypertension: Systolic pressure ≥140, Diastolic pressure <90
If a patient's systolic and diastolic blood pressures belong to different grades, the higher grade shall prevail. Isolated systolic hypertension can also be classified into grades 1, 2, and 3 according to systolic blood pressure levels.

Risk Factors for Hypertension in China

The etiology is unknown, but factors related to its onset include:

1. Age: The incidence rate tends to increase with age, with a high incidence in those over 40 years of age.

2. Salt Intake: High salt intake is associated with a high incidence of hypertension. When salt intake is <2 g/day, hypertension is almost nonexistent; 3-4 g/day, the incidence rate is 3%; 4-15 g/day, the incidence rate is 33.15%.

3. Weight: Obese individuals have a high incidence rate.

4. Heredity: Approximately half of hypertension patients have a family history.

5. Environment and Occupation: Noisy work environments and excessively stressful mental work are prone to causing hypertension. The incidence rate of hypertension is higher in urban areas than in rural areas.

The Dangers of Hypertension

Having hypertension without experiencing symptoms does not mean there is no harm. In the early stages of hypertension, some physical symptoms are not easily detected, such as spasm of small arteries throughout the body. As the disease progresses, small arteries gradually harden, and medium and large arteries develop intimal lipid deposits, forming atherosclerotic plaques and thrombi. This change frequently occurs in the coronary arteries, cerebral arteries, and renal arteries. Therefore, the absence of symptoms in hypertension does not mean it is harmless; it slowly damages the heart, brain, and kidneys, making it a veritable "silent killer." Clinical data shows that approximately 50% of young and middle-aged adults with hypertension are asymptomatic or experience occasional dizziness, headaches, or other atypical symptoms, and many are unaware they have the disease. If left untreated, the harm of hypertension will be maximized. Sustained high blood pressure can damage the heart, brain, kidneys, and aorta, ultimately leading to serious complications such as cerebral hemorrhage, heart failure, and kidney failure, severely impacting health and even life. Without timely treatment, the average lifespan of a patient with hypertension can be shortened by 20 years! Hypertension poses significant risks to organs such as the brain, heart, kidneys, and eyes.

Hypertension damages the brain.

Hypertension can cause stroke (cerebral hemorrhage, cerebral infarction), transient ischemic attack (TIA), etc. Data shows that 70% of strokes are related to hypertension, and stroke is a major cause of vascular dementia.

Hypertension damages the heart.

High blood pressure also has a significant impact on the heart. Data shows that 20%–30% of hypertensive patients also have left ventricular hypertrophy, and 50% of myocardial infarctions are related to hypertension. Simultaneously, hypertension increases the risk of coronary heart disease by 2.6 times and the risk of heart failure by 6 times.

High blood pressure damages the kidneys.

Long-term hypertension increases glomerular pressure. If hypertension persists for 10–15 years, the glomeruli are damaged, and the renal arterioles become diseased, leading to decreased kidney function or kidney failure. In patients with isolated hypertension lasting 15 years, 42% will experience kidney damage, and severe hypertension can increase the risk of uremia by 11 times.

High blood pressure damages the eyes.

It is reported that 78% of hypertensive patients have retinal lesions. High blood pressure can lead to decreased vision, and in severe cases, blindness.