Low blood pressure, or hypotension, is a condition where blood pressure values are generally below 90/60 mmHg. Blood pressure refers to the pressure exerted by the blood on the walls of the arteries. For the body's vital functions to operate properly, it is critically important for blood pressure to remain within specific ranges. When blood pressure drops too low, symptoms such as dizziness, fainting, weakness, blurred vision (or temporary darkening of vision), and a feeling of lightheadedness may occur. Normal blood pressure values are generally considered to be between 90-120 mmHg for systolic (upper) blood pressure and 60-80 mmHg for diastolic (lower) blood pressure. 120/80 mmHg is generally referred to as the ideal or optimal blood pressure value. Consistently elevated blood pressure above 140/90 mmHg is defined as high blood pressure (hypertension).