Blood pressure is exactly what it sounds like. It’s the force of your blood as it pushes against the walls of the tubes called arteries. Your beating heart pressurizes your blood so that it can be pumped from your heart to your arteries and through your whole body. You need to have some blood pressure. After all, without any pressure, your blood wouldn’t move through your body at all and, well, to be blunt about it, you’d be dead. Your blood pressure changes depending on what you’re doing. If you’re doing jumping jacks, you can be assured that your heart is beating more rapidly and your blood pressure is higher than if you were resting. What doctors consider ‘normal’ can be different for different people. But some people have what everyone would consider high blood pressure regardless of what they’re doing. Blood pressure higher than it should be can happen for a variety of reasons, only some of which doctors currently know. There aren’t generally any direct effects of elevated blood pressure. But doctors do believe that elevated blood pressure levels can increase people’s risks for having serious medical problems. Therefore, your grandmother’s doctor may have suggested that she make some changes — a low-fat, low-salt diet, more exercise, or even medication that can often help to lower blood pressure levels. So next time you want to offer your grandmother a snack, instead of salty potato chips, offer her salt-free pretzels!