Modern physicians say normal blood pressure takes no account of age. A reading of 120mm/80mm is normal regardless, according to Mayo Clinic staff. But early 20th century blood pressure cuff users followed a "100-plus-age" rule of thumb to determine what was normal for age. Early 21st century doctors accept increased "normal rates" as patients age, but within a much more limited range, according to the Mayo Clinic.
Two figures define our blood pressure. The higher (systolic) reading shows pressure when the heart is pumping, the lower (diastolic) when the heart is resting between beats. Pressure is the volume of pumped blood and the resistance to the blood flowing in the veins. If the heart pumps a lot of blood and the veins are narrow, the blood pressure will be high (hypertension).
According to the Mayo Clinic, high blood pressure (hypertension) typically develops over many years and affects nearly everyone eventually. Fortunately, high blood pressure is easily detected and controlled. High blood pressure occurs most often in people over 35. Men have a greater risk of high blood pressure than women, until age 45. From ages 45 to 54, men and women are similarly at risk. After age 55 and menopause, women are more likely to develop high blood pressure, according to the Mayo Clinic.
Factors over which you have no control include race. According to the Mayo Clinic, hypertension often develops at an earlier age among blacks than it does whites (see Resources). The serious complications of hypertension, such as stroke and heart attack, also are more common among black races, according to the Mayo Clinic. Family history is also a factor in determining risk.
Diet and Exercise
It's harder with ageing bodies, stiff knees and sore backs to exercise like a 20-year-old. But, say Mayo Clinic staff, extra weight means more blood circulating and pressure on the artery walls goes up. Be careful of what you eat as well as how much. Keep salt (sodium) intake down; it can cause fluid retention. Increase your potassium, as it balances the sodium. Take vitamin D. Limit alcohol. Continue to exercise. Stop smoking, as tobacco raises your blood pressure and the chemicals in the tobacco can cause arteries to narrow, say Mayo Clinic staff.
Dr. Duane Graveline, a former NASA astronaut and family doctor, says the 100+age guideline for "normal" blood pressure was around for decades. He wonders if modern views on what is normal blood pressure arise from drug company involvement. "In the 1970s, the target limit for initiating drug treatment was 160/95. This has now become 140/90, with a large number of organisations listed as in agreement," he says.