Be alert to secondary hypertension and its characteristics in the elderly.

When should secondary hypertension be ruled out?

Generally, when hypertension is diagnosed, a comprehensive physical examination should be conducted to rule out secondary hypertension and to comprehensively assess the patient's physical condition. Secondary hypertension should be investigated in particular if hypertension is accompanied by the following:

(1) Age of onset of hypertension <30 years.

(2) Severe hypertension (grade 3 hypertension).

(3) Poor antihypertensive effect, blood pressure is difficult to control.

(4) Hematuria, proteinuria, or a history of kidney disease.

(5) Snoring and sleep apnea during sleep.

(6) Elevated blood pressure accompanied by limb muscle weakness or paralysis, often occurring periodically, or accompanied by spontaneous hypokalemia.

(7) Paroxysmal hypertension, accompanied by headache, palpitations, pale skin, and excessive sweating during attacks.

(8) Lower limb blood pressure significantly lower than upper limb blood pressure, with a difference of more than 20 mmHg between the two upper limbs, and weakened or impalpable pulsation of the femoral artery. (9) Long-term oral contraceptive users.

What are the characteristics of hypertension in the elderly? Currently in China, the elderly are defined as those over 60 years of age. With increasing age, the prevalence of hypertension also increases. Its characteristics differ from those of middle-aged and young adults, mainly in the following ways:

(1) Isolated systolic hypertension is common, with increased pulse pressure: In elderly patients with hypertension, the compliance (or elasticity) of the large arteries is reduced, resulting in poor buffering capacity for cardiac contraction and relaxation. Therefore, systolic blood pressure is often higher, diastolic blood pressure is lower, and pulse pressure is larger. Isolated systolic hypertension is common. As mentioned earlier, pulse pressure is a reliable indicator of arterial stiffness and has a high positive correlation with prognosis. When pulse pressure > 65 mmHg, the incidence of cardiovascular and cerebrovascular events increases significantly.

(2) Large blood pressure fluctuations: The sensitivity of baroreceptors decreases in the elderly, and their blood pressure regulation function declines. The range of blood pressure fluctuations is significantly larger than in middle-aged and young adults. Therefore, orthostatic hypotension is more likely to occur; they are more sensitive to changes in climate, and hypotension after eating is common.

When measuring blood pressure in the elderly, it is especially important to emphasize that measurements should be taken under conditions of sufficient rest and calm. The difference in blood pressure between measurements taken after sufficient rest and those taken after activity in the elderly can be 20-50 mmHg. If medication is taken hastily, it may result in excessively low blood pressure. Some elderly people are very concerned about their blood pressure, and if their blood pressure is measured without sufficient rest and relaxation, it may be higher, leading them to repeatedly measure it. Such repeated measurements will only raise the blood pressure further. Therefore, it is not advisable to repeatedly measure blood pressure at this time.

(3) Many and serious complications: 40% of elderly hypertensive patients have complications, significantly higher than younger people. Most also have cardiovascular and cerebrovascular diseases, and due to decreased metabolic capacity, abnormal blood lipids and abnormal blood sugar are common.

(4) "White coat hypertension" is common: "White coat hypertension" refers to a patient whose blood pressure is ≥140/90 mmHg when measured in a hospital clinic, but <135/85 mmHg when measured at home. This situation may be due to the patient's excessive sensitivity to psychological stress and mostly occurs in the early stages of persistent hypertension. Studies have shown that blood pressure can still cause harm to the body in this situation. 24-hour ambulatory blood pressure monitoring helps diagnose "white coat hypertension." The incidence of "white coat hypertension" in elderly hypertensive patients is significantly higher than in younger hypertensive patients, approximately 42%.

(5) False hypertension is common: "False hypertension" refers to a condition where the actual blood pressure is not high, but the blood pressure appears high during measurement. Due to increased arterial stiffness in the elderly, the direct measurement result is lower than the result of a conventional cuff measurement. If medication is taken, it can lead to excessively low blood pressure and poor perfusion of vital organs. Therefore, if elderly individuals experience symptoms of poor cerebral blood supply such as dizziness and weakness, it is important to rule out false hypertension.

Screening method: When deflating the blood pressure, feel for the radial artery pulse on the same side. If a pulsation can be heard but no pulse can be felt during deflation, the measured blood pressure may be false.

(6) Increased treatment difficulty: A large proportion of elderly hypertensive patients (approximately 68%) still have uncontrolled blood pressure after systematic treatment. This is mainly because systolic blood pressure is more difficult to control.