In the 1970s, the top number for normal blood pressure was 100 plus a person’s age. Now we know that numbers that high as you age are very dangerous. Medical science has advanced, but we are still unsure what constitutes the optimal level, the best treatments, and even how to properly measure blood pressure.

There is no disagreement, however, that hypertension – high blood pressure – can lead to heart attacks, stroke, vision defects and dementia. Here are a few facts everyone should know about hypertension:

Hypertension isn’t inevitable even though but blood pressure rises with age

Some people never develop high blood pressure, but most experience an increase in systolic blood pressure beginning around age 40. The reason? Arteries tend to stiffen with age.

Even dangerously high blood pressure may be symptomless

Your blood pressure can be dangerously high and the only way you would know it is by having it measured. Getting a reliable reading, however, is difficult. Blood pressure may vary 30 to 40 points throughout the day. Just having your blood pressure measured may cause it to rise. To accurately measure blood pressure, doctors may have you wear an automated upper-arm monitor which tests your blood pressure several times an hour for 24 hours.

Over 50, you should watch the top number

The top number, (the systolic pressure), measures the force of the heart beat as it pumps blood.The bottom number (the diastolic pressure) measures pressure in the circulatory system. The top number represents the peak force that your arteries and your vital organs experience with each heartbeat. If it gets too high, it can damage your organs and even the lining of the blood vessels.

New medications aren’t necessarily better than the old ones

Doctors often begin treating high blood pressure with diuretics, which are among the oldest hypertension medications available. They work by removing excess salt and water from the body. The newer ACE (angiotensin-converting enzyme) inhibitors block the production of a hormone that raises blood pressure. Angiotensin II receptor blockers inhibit the same hormone. Research now shows that the newer medications may be no more effective than diuretics, even though they may cause fewer side effects. Prescribing ineffective medications to control blood pressure is a growing field of healthcare fraud.

Healthy lifestyle works as well as a pill

Restricting salt and consuming plenty of fruits and vegetables can lower high blood pressure by about 5 points. Losing weight is also beneficial. Dropping 11 pounds can reduce systolic blood pressure by more than 4 points. Salt restriction is controversial, but as people age, they tend to add more salt as their sense of taste fades. There is a lot of hidden salt in processed foods, as well.

Coffee raises blood pressure, but only temporarily

Medical scientists have known for a long time that caffeine raises blood pressure. But the good news is that the rise only lasts for about three hours and there appears to be no long-term detriments.