Blood pressure is the force of blood against the walls of your arteries. Blood pressure rises and falls during the day. Blood pressure tends to be higher in the morning and lower in the late afternoon and evening. When blood pressure stays elevated over time, it is called hypertension. Hypertension is dangerous because it makes the heart work harder and contributes to atherosclerosis (hardening of the arteries). It increases both the risk of heart disease and stroke. A blood pressure level of 140/90 mmHg or higher is considered high. If your blood pressure is between 120/80 mmHg and 139/89 mmHg, then you have prehypertension. Historically, prehypertension was not felt to be harmful and ignored. A new study in the journal Neurology shows that this thinking is incorrect. It demonstrates that people with prehypertension have a significantly increased risk of stroke. They found that those with blood pressures in the prehypertensive range were 66% more likely to have strokes than those with ideal blood pressures, below 120/80. The risk rose as the numbers did, nearly doubling at levels above 130/85. The link showed up whether or not people had other risk factors, such as diabetes and smoking. Multiple studies have showed that the higher the blood pressure, the higher your risk of stroke, heart attack, heart failure and kidney disease. The good news is that high blood pressure can be reduced naturally. The number one way to lower blood pressure naturally is by losing weight. Even losing small amounts of weight such as 10-20 pounds can significantly lower your blood pressure without medication. Exercise is also a great way to lower blood pressure naturally. Regular aerobic exercise (20-30 minutes 4-5 times a week) has been shown to have beneficial effects in lowering blood pressure. Finally eating a healthy diet low in salt and high in fruits and vegetables can also help lower blood pressure naturally. Hypertension has been called the silent killer. Now we know even mildly elevated blood pressures are dangerous. If your blood pressure is high, take action now before damage has been done.