Do you often feel light-headed or dizzy when you stand? Does your vision blur at the same time? If you are elderly or diabetic this can be an indication that your blood pressure has fallen suddenly.If you have high blood pressure it is especially important that you recognise this happening. According to the Hypertension Guidelines for Bermuda released in September, physicians should measure the blood pressure of the elderly and diabetics in both of their arms while they are sitting, and also while they are standing.Standing causes 500 to 700ml of blood to pool in the legs, so there is less blood for the heart to pump. This results in a decrease in blood pressure.There are special cells near arteries in the neck that detect the decrease in pressure and trigger the heart to pump more blood faster, until the pressure is stabilised.Over a quarter of adults in Bermuda have hypertension. Body & Soul has partnered with the Department of Health in its hypertension awareness campaign.At least one article every week will focus on some aspect of the condition.If you have a specific query or concern about hypertension please e-mail gazettehealth[AT]yahoo.com or add your comments to the online version of this article.