A sudden fall in blood pressure can be dangerous. A change of just 20 mm Hg — a drop from 110 systolic to 90 mm Hg systolic, for example — can cause dizziness and fainting when the brain fails to receive an adequate supply of blood. And big plunges, such as those caused by uncontrolled bleeding, severe infections or allergic reactions, can be life-threatening.

Septicemia is a severe infection in which bacteria (or other infectious organisms such as fungi) enter the blood. The infection typically originates in the lungs (as pneumonia), bladder, or in the abdomen due to diverticulitis or gallstones. The bacteria then enter the blood where they release toxins and cause life-threatening and profound low blood pressure (septic shock), often with damage to several organs.

Hispanic Community Health Study/Study of Latinos (HCHS/SOL). The NHLBI supports the HCHS/SOL, which is the most comprehensive long-term study of health and disease in Hispanics and Latinos living in the United States. Study data will pave the way for future research into possible causes of health disparities among Hispanic and Latino communities. Visit Hispanic Community Health Study/Study of Latinos for more information.

With low blood pressure, the patient may feel faint or lose consciousness. This is due to lack of blood flow to the brain, and usually laying the patient supine will help them come round. This is also known as a blackout, and it could be accompanied by a dizzy feeling and light-headedness. Generally, your patient will report trouble focusing, difficulty keeping upright and lack of coordination.

What about our continued evolution? Are we saying that homo sapiens are stuck in time ? Being a science student I am totally puzzled. Our stomach was never made to digest wheat and rice and so many grains and pulseswe eat now but then this how we evolved from the cave dwelling and flesh eating beings to what we are today. Does any doctor estimated the systolic and diastolic of our ancestors ?

"The implications and potential benefits of such healthier lifestyles could be great, particularly since about 22% of the adult population falls into the prehypertensive category," says Chobanian, who is also dean of the Boston University School of Medicine. "In fact, the blood pressure effects of weight reduction or adoption of the DASH eating plan can be comparable to those achieved with any single blood pressure medication."

Unlike high blood pressure symptoms, which are poorly defined and often totally absent, low blood pressure symptoms tend to be more upfront and easily recognizable. The development of symptoms is often a warning sign of a potentially serious underlying disorder. Generally speaking, your blood pressure would need to fall pretty dramatically before symptoms develop.