High blood pressure, also known as hypertension, occurs when the pressure of the blood flowing against the artery walls is above the normal range. Blood pressure is determined by the amount of blood the heart pumps and the blood flow resistance in the arteries. If the heart pumps more blood than normal, and the arteries are narrower than normal, the result is high blood pressure. Untreated high blood pressure can cause serious health problems, including heart attack, kidney failure and stroke. There are two types of high blood pressure: primary and secondary. Primary hypertension is high blood pressure that develops gradually over the course of time, and secondary hypertension is high blood pressure that results from an underlying medical condition.
Most people with high blood pressure do not have any symptoms. High blood pressure can gradually develop over the course of time without any symptoms. Prolonged and untreated high blood pressure may cause headaches, dizzy spells or nosebleeds.
In most cases, the cause of high blood pressure, especially primary hypertension, is unknown. Secondary hypertension may be caused by various conditions or medications including:
Alcohol or illegal drug abuse may also lead to high blood pressure.
Risk factors for developing high blood pressure may include:
Chronic conditions such as kidney problems, hormone problems, diabetes, and high cholesterol may all increase an individual's risk of high blood pressure.
Blood pressure is commonly measured during a physical exam. An inflatable arm cuff is fit around the arm and measures the blood pressure using a pressure-measuring gauge. This gauge yields two sets of numbers. The first number is the systolic reading, which is the pressure when the heart is beating. The second number is the diastolic number, the pressure when the heart is resting. High blood pressure occurs when the systolic reading is at 140 or higher and the diastolic reading is 90 or above.
High blood pressure is often initially treated with lifestyle changes that may include:
Hypertension that does not respond to lifestyle changes alone, is often treated with medication that may include alpha blockers, vasodilators, aldosterone antagonists, and central-acting agents. Treating any underlying conditions can also help to control high blood pressure.
High blood pressure is a serious condition. Left untreated, hypertension may cause:
Controlling blood pressure can reduce the risks of these complications.