Your blood pressure test results can add up to good health—or warn of problems. Are you keeping score? To care for yourself and your family, learn your numbers and keep a record of your blood pressure. If your numbers aren’t perfect, know the targets you and your doctors agree you should shoot for.

The first number you should know is one-third. That’s the share of adults who have high blood pressure, according to the American Heart Association.

But if your blood pressure was high, wouldn’t you know it? Not necessarily. There usually aren’t any symptoms.

High blood pressure (hypertension) can lead to conditions such as heart attack, stroke, and kidney disease. Many problems may be able to be prevented if you get your blood pressure checked and follow the treatment plan that your doctor recommends. A healthy diet, regular exercise, and sometimes medications can help.

Here are the numbers you need to know:

• Optimal blood pressure: lower than 120/80 mm Hg
• Prehypertension: 120–139 or 80–89 mm Hg
• High blood pressure:
  • Stage 1: 140–159 or 90–99 mm Hg
  • Stage 2: 160 mm Hg or higher or 100 mm Hg or higher

High blood pressure that’s controlled with medication should be lower than 140/90 mm Hg. If you have diabetes, it should be lower than 130/80 mm Hg.