Most people understand that high blood pressure is not a good thing. However, low blood pressure (hypotension) may likewise be bad news as it could be linked to an underlying health condition.
Blood pressure is the measure of the force of the blood against the artery walls. While high blood pressure can lead to gradual damage to the body’s organs, low blood pressure can also affect our health. At present, the World Health Organization (WHO) has not established specific standards to define low blood pressure, but generally, a systolic blood pressure (SBP) reading of less than 90 mmHg and a diastolic blood pressure (DBP) reading of below 60 mmHg is considered hypotension.
Some patients with hypotension will experience symptoms such as: blurred or fading vision, dizziness, fainting, fatigue, difficulty concentrating, and nausea. Severe low blood pressure, especially in elderly individuals, can reduce oxygen levels, which may cause damage to the heart and brain.
A sudden fall in blood pressure is also dangerous. For example, a fall in SBP from 110 mmHg to 90 mmHg may lead to dizziness and shock, the latter of which may cause rapid, shallow breathing, a weak pulse, and cold, clammy skin. If a patient experiences a sudden drop in blood pressure or the above symptoms, consult a doctor as soon as possible.
Yes, some cases of hypotension are associated with the below conditions. Low blood pressure, therefore, is often a warning sign of an underlying health problem.
- Dehydration: When there is an inadequate intake of water, the body becomes dehydrated and the amount of blood decreases, which causes blood pressure to drop. Fever, vomiting, severe diarrhea, and strenuous exercise may also lead to dehydration and subsequently low blood pressure.
- Lack of nutrients: Insufficient vitamin B-12, folate, and iron may lead to anemia and low blood pressure.
- Heart problems: A heart attack, heart valve disease, or other problems can lead to low blood pressure.
- Endocrine disorders: Conditions such as Addison’s disease may lead to a fall in blood pressure. Low blood sugar can also lower blood pressure.
- Pregnancy: Blood pressure may drop due to the rapid expansion of blood vessels. This generally returns to normal after giving birth.
Other conditions that may cause low blood pressure include: excessive blood loss, severe infection (such as sepsis), severe allergic reaction, and use of medications such as diuretics, Parkinson’s disease medication, antidepressants, heart medication, etc.
The doctor will first conduct a consultation to assess the patient’s condition. If further investigation is needed, the following tests may be done:
- Blood test: to determine whether high/low blood sugar or anemia is the cause of low blood pressure
- Electrocardiogram: checks the heart’s rhythm and electrical activity to see whether low blood pressure is caused by heart disease
- Tilt table test: some patients experience a sudden drop in blood pressure when they change positions (such as from lying down or squatting to sitting/standing up), which is a condition known as postural hypotension. Commonly seen in patients over 65, this type of low blood pressure may be further assessed with this test, which monitors heart rate and blood pressure when the body changes position.
Not necessarily. Patients may try adjusting their lifestyle habits first to see if there is any improvement. The following recommendations target the abovementioned underlying health conditions:
- Drink more water and less alcohol: a higher intake of water increases the amount of blood in the body while a lower consumption of alcohol reduces the loss of fluids, both of which help to alleviate low blood pressure.
- Pay attention to body positions: avoid bending or lying down suddenly or getting out of bed and changing positions (such as from squatting to standing) abruptly to prevent postural hypotension.
- Eat small, low-carb meals: some elderly patients with autonomic nervous system diseases such as Parkinson’s disease may experience postprandial hypotension one or two hours after a meal. Eating small, low-carb meals helps reduce the severity of symptoms.
- Wear compression stockings: these specially designed socks help increase blood flow and alleviate low blood pressure.
For some patients, low blood pressure is caused by certain medications. Under guidance from a doctor, patients may opt to change, stop, or reduce the amount of medication they are taking, but under no circumstances should they adjust their medication on their own accord, as a fluctuating blood pressure is very dangerous. If blood pressure remains low even after numerous attempts to elevate it, or if the cause of low blood pressure cannot be determined, the doctor may prescribe medication.