While normal blood pressure is 120/80, low blood pressure is characterized as less than 90/60. In younger people, low blood pressure with no symptoms (hypotension) is not a cause for concern. In older adults, however, it can be serious if the brain and other organs do not receive adequate blood flow. Symptoms of low blood pressure may include dizziness, and may occur especially when standing up from a sitting or lying down position. Causes include pregnancy, arrhythmia, medication side effects, and more. Treatments may include eating more salt in your diet, drinking more fluids, and more. Follow the links below to find WebMD's comprehensive coverage about how low blood pressure is caused, its symptoms, how to treat it, and much more.