What Are Abnormal Blood Pressure Number Ranges?

Abnormal blood pressure ranges fall into elevated, stage 1 hypertension, stage 2 hypertension, hypertensive crisis, and low blood pressure hypotension.

It can be a concerning moment when a doctor takes your blood pressure. There’s a lot to understand about this set of numbers, so here’s a look at normal and abnormal blood pressure numbers and what it means if your scores are out of the ideal range.

Blood pressure reflects how your heart is working. Specifically, it measures the blood pushing against the arteries that carry the blood throughout your body.

If your blood pressure is too high — known as hypertension — it can place stress on your heart. This can cause damage to blood vessels and eventually organs such as the heart and kidneys.

While low blood pressure is not automatically cause for concern, it can be problematic if it causes dizziness, nausea, or fainting.

About one-third of adults have high blood pressure, and that number jumps to two-thirds in adults over 60. Since there are no initial symptoms — it is often called the "silent killer" — the only way to know for certain that you have hypertension is to have a blood pressure test.

In addition to the symptoms mentioned above, the following could be signs that you have low blood pressure, known as hypotension:

• Dehydration
• Blurred vision
• Cold, pale skin
• Rapid and shallow breathing
• Fatigue

Your blood pressure can be abnormal due to factors beyond your control, such as age or family history. Black people are typically more likely to develop high blood pressure than those who are white or Hispanic.

People with diabetes can be at higher risk. High blood pressure can also develop during pregnancy.

A number of lifestyle factors can contribute to high blood pressure, including:

• Obesity
• Drinking alcohol excessively
• Not enough potassium in your diet
• Too much sodium
• Tobacco use
• Lack of physical activity

Causes of low blood pressure can include:

• A lack of vitamins B-12 and folic acid
• Heart problems such as an abnormally low heart rate or problems with heart valves
• Some medications, such as diuretics and certain heart medications
• Narcotics and alcohol

The Centers for Disease Control and Prevention recommends that you check your blood pressure numbers regularly and record those results for your next doctor’s visit. You can check your pressure with a home cuff, or at a local pharmacy. However, remember that checks you complete on your own may vary, and your scores should be confirmed by a medical professional — particularly if any of the factors mentioned among the causes above apply to you.

Blood pressure is measured in two numbers: the systolic and diastolic pressure scores. The systolic number looks at the pressure when your heart beats, and the diastolic pressure looks at the pressure between beats.

If a systolic number is 110, and a diastolic number is 70, then the pressure would read as “110 over 70” and be written as 110/70 mm Hg. The “mm” stands for millimeters of mercury, while the Hg is the symbol for metallic mercury.

When your blood pressure runs higher than the normal score, it can be considered stage 1 hypertension, advance to stage 2, or be called a hypertensive crisis. This is a score so high that it requires immediate attention.

Medical professionals measure blood pressure using a cuff that fills with air. The cuff is wrapped over your upper arm and inflated. The professional will then read your pressure manually, using a stethoscope and gauge. Or some may use a digital cuff to find the reading.

For an ideal, or normal blood pressure range, the American Heart Association recommends the following:

• The systolic (top) number should be under 120. 
• The diastolic (bottom) number would ideally be below 80. 

Many people have scores that are above what's considered normal. According to the American Heart Association, the following ranges would be concerning:

• Elevated pressure: systolic number (top) between 120 and 129, with the diastolic number (bottom) below 80
• Hypertension, stage 1: systolic number between 130 and 139, or a diastolic number between 80 and 89
• Hypertension, stage 2: systolic number of 140 or higher, or a diastolic number of 90 or higher
• Hypertensive crisis: systolic number higher than 180, and/or a diastolic number higher than 120

If your blood pressure regularly runs high, there’s plenty you can do to get it back in the normal range. Your doctor may recommend medications to lower your score, as well as changes in lifestyle.

In addition, the American Heart Association recommends the following health efforts:

• Maintain a healthy weight.
• Eat plenty of fruits and vegetables and switch to low-fat dairy.
• Shoot for 90 to 150 minutes of exercise per week, including aerobic and strength training.
• Reduce sodium in your diet.
• Limit alcohol to one to two drinks per day or less.

Remember to check with your doctor when making lifestyle changes to make sure these general recommendations are appropriate for your specific health conditions.

Low blood pressure won’t necessarily require treatment if it doesn’t cause any symptoms. If treatment is called for, it will depend on the underlying causes and specific symptoms.

Ideally, you'll be able to keep your blood pressure numbers in the normal range. The key is to monitor your blood pressure, work with your doctor, and keep on top of lifestyle recommendations. This can keep your heart, and therefore the rest of you, healthier for years to come.