Which is More Dangerous, High Blood Pressure or Low Blood Pressure?

You probably already know that high blood pressure is a dangerous, sometimes life-threatening health problem. But it’s also possible to hit the other extreme and develop low blood pressure.

Both of these conditions are technically considered abnormal, or outside normal blood pressure readings. But is one more dangerous than the other? It probably depends on the underlying cause of each condition specifically.

What causes high blood pressure?

High blood pressure

High blood pressure | Zinkevych/iStock/Getty Images

While there isn’t always one definite “cause” of high blood pressure, doctors do look at the number of risk factors that may have contributed to its development. They may note that both your parents had it and that you have high cholesterol, for example, and guess both those reasons likely led to your condition.

Some of the most common factors that may increase your risk of developing high blood pressure include:

  • Age (over 50)
  • A family history of high blood pressure
  • Chronic stress
  • Physical inactivity
  • Smoking and/or excessive alcohol consumption
  • Overweight or obesity
  • Unhealthy eating patterns
  • High cholesterol.

High blood pressure increases your risk of a number of potentially life-threatening health conditions, such as diabetes and heart disease.

What causes low blood pressure?

Unlike high blood pressure, low blood pressure occurs when your heart pumps blood through your arteries with less force than is considered normal. For many people, low blood pressure does not cause any problems. But this isn’t always the case.

There are many possible causes of low blood pressure, and some of them are more common than you might think — such as hypothyroidism, certain medications, and pregnancy. People with certain heart problems also often experience low blood pressure.

However, there are also some more extreme causes of low blood pressure, such as blood loss, serious infection, and anaphylaxis. If these are the reasons for your low blood pressure, you probably have more pressing concerns to treat first.

Which is more dangerous?

Blood pressure

Blood pressure | Ronstik/iStock/Getty Images

Both high blood pressure and low blood pressure can cause serious harm. But one is more of a short-term concern (symptoms come and go), and the other is something that can hurt you more and more the longer you live with it.

According to the American Heart Association, doctors really only consider low blood pressure to be dangerous if it causes symptoms such as dizziness, fainting, dehydration, or shallow breathing.

Some of these symptoms can increase your risk of becoming injured. For example, if you feel lightheaded or become dizzy, you risk falling. You should still alert your health care provider if you experience these symptoms frequently, in case there is a treatable underlying cause.

High blood pressure is a “silent” health condition that develops slowly over many years. Initially, it may not cause you any harm. But if it goes untreated, it can lead to a heart attack or stroke. It’s considered extremely dangerous because many people don’t know they have it (it doesn’t have symptoms) until they need medical attention.

Doctors can detect it through a series of visits, but it’s impossible to get a clear diagnosis if you don’t see a doctor regularly.

Abnormal blood pressure comes with health risks. If you’re concerned about your blood pressure — high or low — your health care provider can tell you if your health is at risk and what you can do to stay safe.