2008年1月4日星期五

High Blood Pressure

Recent estimates have indicated that one in three adults in the USA has high blood pressure and that a third of these people are unaware of their condition. Your blood pressure is quite simply the force of the blood on the artery walls when the heart beats (systolic pressure) and when it rests between beats (diastolic pressure). The normal values are less 120 mm Hg systolic and less 80 mm Hg diastolic. If your blood pressure is 140-159 mm Hg Systolic over 90-99 mm Hg Diastolic then this is classified as High blood pressure or Hypertension.
There are many causes of high blood pressure; in 90-95% of cases the actual cause cannot be discerned. Nerve impulses cause your arteries to dilate (become larger) or contract (become smaller). If these vessels are wide open, blood can flow through easily. If theyre narrow, its harder for the blood to flow through them, and the pressure inside them increases. High blood pressure may occur at this point. The remaining cases high blood pressure may be caused by kidney abnormalities, an abnormality of the aorta, the narrowing of certain arteries.
Blood volume also affects blood pressure - the more blood in the body, the higher the amount of blood returning to the heart and the resulting cardiac output and higher the blood pressure. Arteries thickened by fatty tissue increase the resistance of the blood as it flows and this increased the resistance will contribute to higher the blood pressure. Other factors could also affect blood pressure like blood viscosity or stickiness. This is called your triglyceride levels. A raised triglyceride can be caused by a high alcohol or carbohydrate diet, being over weight or having poorly controlled blood sugars.
Keeping fit through a balanced diet and exercise is an important way to decrease high blood pressure. There is a direct link between rising blood pressure or hypertension and being overweight. Exercise improves the condition of the thickened arteries which helps in the treatment of high blood pressure by making the heart stronger. A stronger heart pumps more blood efficiently, which means that the heart doesnt have to work as hard. However anyone with high blood pressure should consult a doctor before any exercise plan.
Research has also shown some evidence that exercise reduces the release of nor epinephrine, which is a hormone that raises blood pressure by constricting arteries and increasing the heart rate.
Aiming for and maintaining an ideal body weight is really important in the treatment of high blood pressure. If you are overweight or obese, ask your doctor for a referral to a dietitian who can help you make permanent, achievable changes to the way you eat to assist with weight loss.
Cutting down on your alcohol intake, is very important - as this has a significant role in boosting blood pressure. Women should limit their intake to one drink per day and men two. Smoking injures blood vessel walls and accelerates the hardening of the arteries. Although it does not directly cause even though it does not cause high blood pressure, smoking is bad for anyone, especially those with high blood pressure
Dietary changes can really contribute to the treatment of high blood pressure. In studies sponsored by the National Institutes of Health, the DASH (Dietary Approaches to Stop Hypertension) eating plan has been shown to be effective. Essentially this plan involves consuming increased amounts of fruit and vegetables and choosing low-fat or non-fat dairy products. Studies have shown that eating fruits, vegetables, and low-fat dairy food and proteins as well as foods with lower saturated fat, total fat, and cholesterol, lower blood pressure and promote overall fitness. Whole grains, poultry, fish and nuts with lower fat content are good choices for the heart. Details of the DASH diet can be found at: http://www.nhlbi.nih.gov
Foods with large amounts of saturated and trans fats such a fatty cuts of meat, fast food, fries, cakes and cookies should be kept to a minimum. This will also help with limiting the amount of sodium or salt in the diet. You should also try to avoid adding salt in your cooking and at the table, to limit gravy powders, salty soups and seasoning as well as salted crisps and nuts.
So why not have a go at these small changes - they really can make a difference in the treatment of high blood pressure!