For some people low blood pressure is normal. Here's when to talk to your doctor

About half of American adults have high blood pressure, but low blood pressure may also be cause for concern, according to the Centers for Disease Control and Prevention.

Shaline Rao, MD, a cardiologist at NYU Langone Hospital, Long Island, explains that one's blood pressure should be kept at levels that are "not too high and not too low," but in a "healthy range which is typically between 90/60 to 140/80."

A healthy blood pressure level is essential because blood pressure that's too high, also called hypertension, puts one at risk for heart attack, heart disease, or stroke. Blood pressure that's too low, also called hypotension, is less dangerous and life-threatening, but can still pose health risks.

Just as one can lower high blood pressure through diet, behaviors, and lifestyle choices, it's also possible to raise one's blood pressure to reduce instances of hypotension.

What is dangerously low blood pressure?

When checking one's blood pressure, two numbers are always reported: The top number is called systolic blood pressure and measures the pressure in one's arteries every time the heart beats. The second number, called diastolic blood pressure, measures the pressure in one's arteries when the heart rests between beats.  When one's blood pressure level goes lower than 90/60, it may be cause for concern in some people.

If one's blood pressure drops too low, blood is not fully flowing to the brain and arteries, so one's vital organs will not be getting enough oxygen or nutrients.

What causes low blood pressure?

Hypotension can be caused by various activities or conditions including dehydration, age, pregnancy, blood loss from an injury, diabetes, as a side effect of medications taken to control depression, high blood pressure, or Parkinson's disease, or as a result of "deficiencies in B12, folate and iron," says M. Scott Dawson, MD, a cardiologist at Inspira Medical Group Cardiology.

Orthostatic hypotension is a type of low blood pressure that occurs from standing after being in a sitting position or lying down. It happens because one's body "doesn't respond appropriately to the change in position and a transient drop in blood pressure occurs," explains Dawson.

Neural Hypotension is another type of low blood pressure, and is more common in children and younger adults. "It is caused by faulty signals between the brain and the heart," says Dawson.

What are the symptoms of low blood pressure?

Though some people with chronic low blood pressure function normally, don't experience symptoms, and shouldn't be alarmed, blood pressure that drops rapidly can become life-threatening and may be indicative of serious medical conditions or shock. "In healthy individuals, low blood pressures can be normal," explains Rao, "but if your blood pressure is low and you feel symptoms such as dizziness, fainting, or wobbly legs when trying to walk, you should discuss them your healthcare provider."

More immediately concerning symptoms of low blood pressure include an inability to stand up, trouble speaking, or a blurring of one's vision. The National Heart, Lung, and Blood Institute notes that signs of shock relating to a sudden drop in blood pressure include cold and sweaty skin, rapid breathing, a blue skin tone, or a weak and rapid pulse. "Call 9-1-1 if you notice signs of shock in yourself or someone else," the agency warns.

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How can I safely raise blood pressure?

Malissa Wood, MD, the associate chief of cardiology for diversity and health equity at Massachusetts General Hospital, advises for anyone worried about their low blood pressure levels to consult their physician to see if the condition is normal for them or not (i.e. pregnancy, a side effect of the medication they're on, etc.), but says there are many instances when a doctor will advise increasing it. "Individuals with abnormally low blood pressure or those who experience positional drop in blood pressure may be instructed to avoid standing for long periods of time, use of pressure support stockings, increased intake of salt under a clinician’s guidance, and sometimes medications may even be required to increase the resistance of the blood vessels," she explains.

What should I eat if my blood pressure is low?

Minor adjustments to one's diet and everyday behaviors can also be helpful in reducing instances of hypotension. "Increasing hydration, limiting alcohol, eating small meals that are low in carbs, and being careful not to sit with your legs crossed can all help increase your blood pressure and reduce symptoms," offers Dawson. "As with high blood pressure, you should talk with your doctor about the best strategies for managing hypotension."

Read more about common health concerns here:

Dehydration and high blood pressure:  What you need to know.

High blood pressure and your health: What you need to know to lower it

This article originally appeared on USA TODAY: What is dangerously low blood pressure?