Certain heart conditions can cause low blood pressure when the heart is unable to pump enough blood. Heart attack, bradycardia, or low heart rate, heart valve disorders, and heart failure can all cause low blood pressure. Low cardiac output results when the heart's pumping ability is impaired. Heart rate drops when the amount of blood being circulated throughout the body decreases. Pericarditis is another heart condition that causes fluid to accumulate. This restricts the heart's ability to fill with blood to pump to the rest of the body. Tachycardia, or fast heart rate, can also cause low blood pressure. Because the heart is beating faster, the lower chambers of the heart do not have time to fill completely with blood before the heart contracts pushing blood into the arteries. This reduces the amount of blood being pumped lowering blood pressure.
Blood Loss
Internal bleeding or blood lost through a serious injury or burn decreases blood volume in the body causing blood pressure to drop, sometimes dangerously low. When blood pressure is too low, there is not enough blood circulating through the body. This means that an inadequate supply of oxygen is being delivered to the brain and other vital organs like the heart and kidneys. If a person loses too much blood, a blood transfusion may be necessary. Left untreated, low blood pressure from severe blood loss can cause brain damage, coma or even death.
Dehydration
Severe vomiting and diarrhea, fever, use of diuretics, heat exhaustion and strenuous exercise can lead to dehydration, a common cause of low blood pressure. When dehydration triggers low blood pressure the condition can cause symptoms such as dizziness, weakness and fatigue. Fainting can be another sign that blood volume is too low. Dehydration occurs when fluids in the body are depleted and not replenished to normal levels. Many times, older individuals fail to drink enough fluids when taking diuretics. Hypovolemic shock caused by a traumatic injury is a life-threatening complication that occurs when low blood volume causes a sudden drop in blood pressure. As a result, less oxygen is being distributed to the body's cells and tissues. This type of severe blood loss can cause organs in the body to stop functioning, and therefore, is considered to be a medical emergency, as kidney and brain damage can occur. Individuals who are severely dehydrated need to go to a hospital to receive fluids intravenously.
Anemia
Low blood pressure is a symptom of anemia, a condition in which the body is unable to produce enough red blood cells. Often caused by an extreme loss of blood, iron deficiency or a lack of vitamin B12 and folate in the diet, anemia is usually characterized by weakness and fatigue. The body needs vitamin B12 and folate to make the red blood cells that carry oxygen. Iron deficiency also causes a decrease in the number of red blood cells produced. A proper balance of nutrients is required for the body to maintain a normal blood pressure. Blood pressure drops when the body's major organs are unable to get the nutrients and oxygen they need from the blood.
