Your blood pressure is a measurement of how much pressure is present in the arteries during the active and resting phase of your heart. The systolic pressure (top number) is the pressure measurement when the heart pumps blood to your body. The diastolic (bottom number) is the artery pressure present when your heart rests in between beats.
Low blood pressure has been defined as less than 90/60 mm Hg; though some experts only classify blood pressure as too low if it causes symptoms. With a great deal of variation in different person’s blood pressure, what may be low for one, may not necessarily be low for another.
Sudden drops (20 mmHg or more) in blood pressure can produce low blood pressure symptoms in some people, yet not drop the blood pressure low enough to be classified as low blood pressure.
Symptoms of low blood pressure are:
- Dizziness, imbalance, or feeling like you’re on a rocking boat
- Difficulty concentrating
- Confusion or anxiety
- Fast, shallow breathing (panting)
- Nausea and/or vomiting
- Cold clammy skin
- Suddenly skin becomes pale or white
When symptoms appear, low blood pressure is confirmed by taking the person’s blood pressure and comparing it to a normal reading for that person.
Determining the cause of low blood pressure may be more difficult to assess. Occasionally when moving from a sitting or lying to a standing position may induce low blood pressure symptoms. This is called orthostatic hypotension and is caused by blood pooling in the lower extremities. Normally this does not cause a problem for most people.
Conditions that alter the volume of blood in the body, reduce the heart’s pumping ability, or medications can cause low blood pressure symptoms.
These conditions include:
- Dehydration-Things such as prolonged vomiting, diarrhea, fever, heat exhaustion, excessive sweating, exercise and heat stroke can lead to dehydration. This loss of fluid volume produces low blood pressure. If the drop is significant enough, it can cause low blood pressure symptoms.
- Moderate or severe bleeding reduces the blood volume and therefore the blood pressure.
- Weakened heart muscle due to damage from heart disease (heart attack, congestive heart failure,) can cause the heart to pump less effectively and lead to low blood pressure.
- Conditions that reduce/impede pumping efficiency in the heart such as coronary such as coronary artery disease, pulmonary embolism, and pericarditis (inflammation and fluid buildup around the heart) often cause low blood pressure.
- Slow heart rate (bradycardia) reduces the amount of blood pumped by the heart, and thereby reducing blood pressure.
- Tachycardia (fast heart rate) that does not allow the heart chambers to fill completely
- Medications and alcohol can significantly lower blood pressure producing symptoms.
Shock is a life threatening condition where the blood pressure drops so low the heart cannot pump enough blood to meet the needs of the brain and body’s other vital organs. Seek emergency medical help immediately, as this is life threatening.
Other treatment depends on what is causing the low blood pressure symptoms. In certain non-life threatening cases, no treatment is chosen. If a medications benefit, outweigh the low blood pressure symptoms, continuing the medication may be opted for. If symptoms are not severe or bothersome, a patient may be instructed to take extra precautions against injury and no other treatment be required.