But if you have chronic low blood pressure as well as difficulty concentrating, it may be because blood is not being moved to ...

Anemia is when you have low levels of red blood cells. When this happens, your organs and tissues have a harder time getting oxygen. You may feel fatigue, weakness, and shortness of breath.

Pressure is measured in millibars. Standard pressure at sea level is 1013 millibars, but large areas of either high or low pressure can occur. Areas of high and low pressure are caused by rising ...