Why Sciatica Muscle Pains Occur. Both the piriformis and the sciatic nerve begin at your tailbone (coccyx). The piriformis crosses directly on top of the sciatic nerve, and this is what causes the problem. When the muscle goes into a spasm it presses down directly onto the nerve, pushing it into the bone underneath. And you get the terrible pain of sciatica.
Low blood pressure. Low blood pressure occurs when blood pressure is much lower than normal. This means the heart, brain, and other parts of the body do not get enough blood. Normal blood pressure is usually between 90/60 mmHg and 120/80 mmHg. The medical name for low blood pressure is hypotension.
diminished tension; lowered blood pressure. A consistently low blood pressure (systolic pressure less than 100 mm of mercury) usually is no cause for concern. In fact, low blood pressure often is associated with long life. However, extremely low blood pressure may be a sign of a serious condition such as shock, massive hemorrhage, hypovolemia, or severe dehydration from nausea and vomiting.