Is hypotension actually more harmful than hypertension?

The question about hypotension is probably one of the most commonly told myths without evidence. In conclusion, hypotension is not a disease. Perhaps this misunderstanding may be caused from the medical condition called “shock,” where there is an acute decrease in blood pressure with severe malfunction of the body and a potentially fatal outcome.

In emergency situations such as severe bleeding or serious decline in the cardiac function, there is indeed a decrease in blood pressure. However, this is a different matter from “chronic hypotension” without a specific cause.

There is no evidence that chronic hypotension is harmful, and there isn’t any theoretical basis to support it. Hypotension merely means that the blood pressure is low, and there is no standard to define hypotension.

Can a person with hypotension suddenly develop hypertension?

Of course, people who had low blood pressure when they were young may have increasing blood pressure as they become older. However, there is clear evidence that those with lower blood pressure have a lower risk of developing hypertension. Some people believe that those with low blood pressure are low in energy and unhealthy, but this is not true, either. It is possible to supply sufficient blood to all parts of the body with a lower blood pressure, so we can say that they have a more efficient body compared to those who need high blood pressure to deliver blood because of hypertension.

However, postural hypotension in the elderly must be noted. With aging, the ability to change the cardiovascular system rapidly decreases, so people can feel dizzy due to the insufficient blood flow to the brain from lower blood pressure when changing position quickly such as from sitting down to standing up or from lying to jumping out of bed suddenly. In case of those with moderate severity, taking care not to change posture quickly can prevent falls and fractures.

Postural hypotension is referred to as a temporary drop in blood pressure when standing up, leading to decreased blood flow to the brain and causing dizziness or temporary loss of vision, or syncope. It is a relatively common condition.

When standing up from a sitting position, it is natural that the blood pools in the lower limbs due to gravity. In normal persons, the autonomic nervous system causes contraction in the lower limb muscles and blood vessels to minimize this effect, causing only a small drop in blood pressure of 10-15 mmHg. However, the slowing down of this reflex due to various causes can lead to a significant drop in blood pressure, causing the above symptoms.

There is an overall decrease in the nervous system function with aging, which is the most common cause of postural hypotension. Other causes include alcohol intake, severe dehydration or sitting in a hot bath for a long time, leading to dilation of the lower limb blood vessels. People can frequently feel dizzy or even faint after a hot bath or shower, which can lead to falling or hitting objects.

There is no specific treatment for this condition, and it is recommended that you get up slowly. If you feel dizzy you should lower your head to the level of sitting or lying down. People tend to recover after standing for a while, leading to recovery of the blood flow to the brain due to reflexes. But in severe cases this can lead to syncope, so it is safer to lower your posture. It also helps to drink sufficient water to avoid dehydration and limit the intake of alcohol. It is also thought that sufficient rest and exercise can help. In cases of patients with a severe condition, medication to increase blood pressure may be taken, but this is not a common treatment as it must be taken for a lifetime, and causes hypertension when lying down.

Fainting or feeling dizzy when standing for a while, other than standing up from a sitting position, or fainting in the bathroom, may be caused by vasovagal syncope, which needs to be seen by a specialist doctor. 

By Sung Ji-dong

The author is a doctor in the Division of Cardiology at Samsung Medical Center and a professor of Sungkyunkwan University School of Medicine. ― Ed.