Blood pressure is the pressure exerted by the blood during circulation on the walls of the blood vessels. It generally refers to the pressure in the large arteries of the circulatory system. The circulatory system of the body functions when the heart beats and circulates blood throughout the body. When blood moves from the heart to all the tissues and muscles of the body, it exerts pressure on the walls of the blood vessels. Blood pressure is one of the main medical examinations done and is part of the vitals including heart rate, respiratory rate, pulse, and oxygen saturation. Blood pressure is measured in systolic pressure and diastolic pressure. It is measured with the help of a blood pressure meter. A manual blood pressure meter consists of a mercury manometer and a digital blood pressure meter contains an oscillometer. The systolic pressure is the pressure on the walls of the blood vessels when the heart muscle is contracted. This is the top number. The diastolic pressure is the pressure exerted on the walls of the blood vessels when the heart is in between beats. This is the bottom number. Blood pressure is measured in millimeter of mercury (mmHg). The blood pressure of a person depends upon many factors. The first is cardiac output, which is the product of the heart rate (number of beats per minute) and the stroke volume (volume of blood pumped per beat). Blood pressure also depends upon total peripheral resistance or the vascular resistance, which is the resistance blood must overcome in order to flow through the blood circulatory system. Blood pressure depends upon another factor called the arterial stiffness. This is the stiffness of the arteries that is caused either due to aging or conditions like arteriosclerosis. Apart from this, blood pressure fluctuates depending upon emotional stress, the physical location of a person with respect to altitude, weather, physical activity, and other preexisting disease conditions. The ideal blood pressure for a person is 120/80; however, systolic levels between 90 and 120, and a diastolic of 60 to 80 are considered as normal readings. Blood pressure readings vary with age and a blood pressure with a systolic reading of 120-139 or a diastolic reading of 80 – 89 is considered pre-hypertensive. When the systolic is 140 to 159 or the diastolic reading is 90-99, it is considered as hypertension stage 1. When the systolic is or above 160 or the diastolic is 100 or higher, it is hypertension stage 2. A blood pressure with systolic higher than 180 or a diastolic higher than 100 is a medical emergency. Hypertension (See: Hypertension) is the presence of high blood pressure. High blood pressure causes many health complications and can lead to heart attack, stroke, kidney ailments and many others. Low blood pressure on the other hand is called hypotension also leads to heart attacks, strokes, and kidney failure. A blood pressure with systolic below 90 or diastolic below 60 is considered hypotension. People with diabetes might experience low blood pressure due to events of hypoglycemia. However, high blood pressure puts people with diabetes at a higher risk of cardiovascular diseases, eye and kidney diseases, and strokes.