Blood pressure is a measure of the outward force exerted by the blood on the arteries in your body. A healthy body has a blood pressure that is just enough to push the blood into all of the smaller blood vessels of your body, called capillaries.
Blood pressure is created by a combination of factors in your body:
- Force of the heart pushing blood out of the heart chambers into the aorta.
- The volume of blood you have circulating in your circulatory system.
- The size of the blood vessels that the blood has to travel through. As the diameter of the blood vessels decrease, it requires greater pressure to push blood through.
Your body has various systems in place to keep your blood pressure within very strict limits. Negative feedback systems are in operation. Sensors in your carotid artery and wall of the aorta monitor blood pressure, and if it gets too high, a signal is sent to the medulla in your brain, which in turn reduces your heart rate, and increases vasodilation (opening up) in blood vessels (called arterioles). This means the same volume of blood is distributed between more blood vessels, so overall blood pressure drops. When blood pressure drops, the opposite happens. Heart rate increases, and vasoconstriction (closing off) occurs in arterioles.
Things can and do go wrong
Various factors can cause high blood pressure (which is called hypertension by the medical community).
There are varying opinions on what measurements actually constitute high blood pressure, but the majority of source agree that:
Greater than 140 mmHg Systolic Pressure, and greater than 90 mmHg diastolic pressure is high. If you have two or more readings taken on different occasions, you may be diagnosed as having hypertension.
Symptoms & Signs of High Blood Pressure
Unfortunately high blood pressure has very few (if any) symptoms, and is often called the “Silent Killer”. You should go to your doctor and get your blood pressure checked frequently. Alternatively you could buy a personal digital blood pressure monitor and make the measurements at home. It could save your life.
What Causes of Hypertension
In most cases, the cause of hypertension is unknown. However, there are some factors which can contribute to it.
- Excessive alcohol
- Salt in the diet
- genetic factors
Blood pressure can also increase in pregnancy, when the patient has kidney problems, or hormonal problems like an over-active thyroid, and even sleep apnea (a condition which causes the sufferer to stop breathing for a short time when asleep).
There are also some medications that can cause increased blood pressure including antacids, oral contraceptives, decongestants and diet pills. Please read the notes that come with any medication you are taking for details on possible blood pressure side-effects.
Risks of Hypertension
If your blood pressure is too high, your heart and arteries are put under stress, and can hate fatal consequences.
- Hypertension causes damage to the walls of your arteries causing them to become less elastic. This hardening of the arteries makes it much easier for harmful cholesterol to stick to your artery wall, reducing the diameter of the blood vessel through which blood must flow. With narrowing of the arteries, your heart must work much harder to push the blood through, and blood pressure rises. Possible consequences include heart attack, stroke, kidney failure, or even the amputation of the leg.
- Risks of heart attack and stroke are greatly increased in patients with high blood pressure.
- Heart enlarges which can cause heart attack.
- Bulging of the arteries outwards. These aneurysms can rupture, leading to blood spilling out into surrounding tissues. If this occurs in the brain, the patient will likely suffer a stroke.
- Blood vessels in the kidneys narrow possibly leading to renal failure.
- Blood vessels in the eyes can burst, causing a deterioration in sight, even blindness.
Treatment of high blood pressure
See our high blood pressure diet page to read about how you can reduce your blood pressure naturally. Also you can read about some of the medications used to treat high blood pressure, and possible side-effects of these drugs.