High blood pressure, or hypertension is a common condition in which the force of blood on the walls of your arteries is often too high. Arteries are the blood vessels that carry blood away from your heart to supply your tissues with oxygen and nutrients.
高血压是一种常见的疾病，病人出现高血压时，动脉管壁的血压往往过高。动脉是将来自心脏的血液运送至组织，为组织提供氧气和营养物质的管道。
In your heart, two chambers, called ventricles, contract with each heartbeat to push blood to your lungs and through your arteries to your body. As blood flows through them, three main factors affect the pressure on your artery walls.
心脏有两个心室，每一次心跳伴随一次收缩。心室收缩时，将血液推入肺部，并经动脉输送至全身。血液流经动脉血管时，影响动脉管壁压力的主要因素有三个。
The first is cardiac output, or the amount of blood your ventricles push out of your heart each minute. Your blood pressure goes up as cardiac output increases. The second factor affecting your blood pressure is blood volume, or the total amount of blood in your body. Blood pressure also goes up as blood volume increases. The third factor that affects your blood pressure is resistance, which is anything working against the blood flow through your arteries.
第一是心输出量，或每一分钟从心脏泵出的血量。血压随心输血量增加而升高。第二个因素是血容量，或机体内血液总量。血压随血容量增加而升高。第三个因素是阻力，阻力指阻碍动脉血流的所有因素。
Several factors contribute to resistance. One resistance factor is the flexibility of your artery wall. Healthy arteries expand with each heartbeat to help reduce blood pressure on the wall. Another resistance factor is the diameter of your arteries. Your body is able to increase the diameter of your arteries to lower your blood pressure, or reduce the diameter to raise your blood pressure. A third resistance factor is blood viscosity, or thickness. In your blood, more particles, such as proteins and fat, increase viscosity.
构成阻力的因素有多个。一个是动脉壁的柔韧性。健康的动脉会随着每一次心跳扩张，以降低血液对管壁的压力。另一个是动脉直径。机体能够增加动脉管壁直径来降低血压，或缩小直径使血压升高。第三个是血液粘度或厚度。血液中存在较多使血液粘度增加的颗粒，如蛋白质和脂肪。
If your blood is thicker, your blood pressure goes up as your heart works harder to push it through your arteries. Your blood pressure can be measured with a device called a sphygmomanometer, or blood pressure cuff. When your heart beats, the pressure of blood on the walls of your arteries is called systolic pressure. When your heart relaxes between beats, pressure on the artery wall is called diastolic pressure.
血液较厚时，血压随着心脏做功增加而升高。我们可以使用血压计或血压袖带测量血压。心脏跳动时，动脉管壁的血压称为收缩压。两次跳动之间心脏放松时的压力称为舒张压。
While your blood pressure may change throughout the day, it should normally be less than 120 millimeters of mercury for systolic pressure, and less than 80 millimeters of mercury for diastolic pressure. If your systolic pressure frequently stays above 140, or your diastolic pressure frequently stays above 90, you have high blood pressure. Over time, high blood pressure will damage the walls of your arteries. Your artery wall may become weak and form an enlargement called an aneurysm. Or the wall may burst and bleed into the surrounding tissue. Small tears in your artery wall may attract certain substances in your blood, such as cholesterol, fat, and calcium, to form a build-up called a plaque.
尽管一天内血压可能会发生变化，但是通常情况下，收缩压小于120mmHg,舒张压小于80mmHg。如果收缩压经常保持在140以上，或舒张压经常保持在90以上，那么我们称病人患有高血压。随着时间的推移，高血压会损害动脉壁，病人的动脉壁可能会变得脆弱，形成动脉瘤。血管壁也可能会破裂，这样血液就会流入周围组织。动脉壁的微小裂口可能会吸引血液中的某些物质，如胆固醇、脂肪和钙，进而形成斑块样的物质。
Blood flow through your artery decreases as the plaque enlarges. Blood cells can stick to the plaque and form solid clumps, called clots, further reducing, or completely blocking your blood flow. Damage to your arteries raises your blood pressure even more by making your heart beat more forcefully. Artery damage and reduced blood flow lead to conditions such as a stroke, heart attack, or kidney disease.
随着斑块增大，动脉血流减少。血细胞会粘附在斑块上，形成固体凝块，即血凝块，进一步减小，或完全阻断血流。动脉损伤会使心跳更加激烈，从而使血压升高。动脉损伤以及血流减少会导致中风、心脏病发作或肾病等疾病。
In most cases, the cause of high blood pressure, or hypertension, is unknown. This type of high blood pressure is called primary, or essential hypertension. Treatment for essential hypertension includes lifestyle changes, such as eating a healthy diet. If you are sensitive to the sodium in salt, your doctor may recommend limiting your intake of salt and highly processed foods. Sodium may cause your body to retain water, which increases both your blood volume and your blood pressure.
大多数情况下，高血压的病因尚不清楚。这种高血压称为原发性高血压。治疗方式包括生活方式改变，如健康饮食。如果病人对盐中的钠敏感，医生可能建议限制摄入盐和高度加工食品。钠可能保持机体水分，从而增加血容量和血压。
Other lifestyle changes that can reduce blood pressure include avoiding excessive alcohol intake, getting regular exercise, losing weight if you are overweight, and quitting smoking. Your doctor may also recommend medications that act on your kidneys, blood vessels, or heart to help reduce your blood pressure.
其它降低血压的生活方式改变包括避免过度饮酒、经常锻炼、减肥（超重的情况）、戒烟。医生也可能建议药物治疗（作用于肾脏、血管或心脏）。
Diuretics, commonly called water pills, cause your kidneys to move more salt and water from your blood into your urine, which reduces your blood volume and pressure. Beta-blockers reduce the workload on your heart by decreasing both the rate of your heartbeat and the strength of your heart's contractions.
利尿剂，通常称为水片剂，可以使血液中较多的盐和水通过肾脏过滤到尿液中，从而减少血容量，降低血压。β受体阻滞剂可以降低心跳频率和心脏收缩强度来减轻心脏工作负荷。
Several types of drugs act directly or indirectly to reduce your blood pressure by relaxing your blood vessels, which increases their diameter. These drugs include ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers, and direct-acting vasodilators.
目前也存在几种直接或间接通过舒缓血管降低血压的药物，如ACE抑制剂、血管紧张素II受体拮抗剂、钙离子通道阻滞剂以及直接发挥作用的血管扩张剂，这些药物可以增加血管直径。
