A blood pressure of 108/70 is a good reading. It falls squarely in the “normal” category, which the American Heart Association defines as a systolic (top number) below 120 and a diastolic (bottom number) below 80. At 108/70, both numbers sit comfortably within that range, well below the threshold for elevated blood pressure and well above the point where most people experience symptoms of low blood pressure.
What the Two Numbers Mean
The top number, 108, is your systolic pressure. It measures the force your blood exerts on artery walls each time your heart beats. The bottom number, 70, is your diastolic pressure, which measures that same force between beats, when your heart is resting. Both numbers are measured in millimeters of mercury (mm Hg).
A reading of 108/70 means your heart is pumping efficiently without putting excessive strain on your arteries. For context, here’s how the AHA categorizes blood pressure in adults:
- Normal: below 120/80
- Elevated: 120 to 129 systolic, with diastolic still below 80
- Stage 1 hypertension: 130 to 139 systolic, or 80 to 89 diastolic
- Stage 2 hypertension: 140+ systolic, or 90+ diastolic
Is 108/70 Too Low?
Some people see a number like 108 and wonder if it’s trending toward low blood pressure. In most cases, no. There’s no fixed cutoff for hypotension the way there is for hypertension. Most doctors consider blood pressure “too low” only when it causes symptoms, not based on the number alone. If you feel fine at 108/70, there’s nothing to address.
The symptoms that signal genuinely low blood pressure include dizziness or lightheadedness, blurred or fading vision, fainting, unusual fatigue, trouble concentrating, and nausea. A sudden drop matters more than a consistently low baseline. A shift of just 20 mm Hg in your systolic reading, say from 110 down to 90, can be enough to make you feel faint, even though 90 itself isn’t dangerously low for everyone. People who consistently run readings around 100 to 110 systolic without any symptoms typically need no treatment at all.
Who Commonly Has This Reading
A blood pressure of 108/70 is especially common in younger adults, women, and people who are physically active. Regular aerobic exercise tends to lower resting blood pressure over time, so runners and other endurance athletes often have systolic readings in the low 100s. Research from the University of Tennessee found that older runners and swimmers maintained resting blood pressure well below the average for their age group, which reflects how cardiovascular fitness keeps arteries flexible and efficient.
During pregnancy, blood pressure naturally dips in the first and second trimesters before rising again closer to delivery. A reading of 108/70 during pregnancy falls within the normal range and is not a cause for concern on its own.
Why Your Reading Can Vary
Blood pressure is not a fixed number. It shifts throughout the day based on your activity, stress level, hydration, caffeine intake, body position, and even the time of day. A single reading of 108/70 is a snapshot. If you took it right after resting quietly for five minutes, it’s likely close to your true baseline. If you took it after exercise, a stressful phone call, or a cup of coffee, the number could be higher or lower than usual.
For a reliable picture of your blood pressure, take readings at roughly the same time of day over the course of a week. Sit with your feet flat on the floor, your arm supported at heart level, and rest for at least five minutes before measuring. The average of those readings is far more meaningful than any single one.
Why Systolic Matters More as You Age
Both numbers contribute to your overall cardiovascular picture, but the systolic number becomes a more important predictor of heart disease risk after age 50. That’s because large arteries stiffen over time, and plaque gradually builds up, pushing systolic pressure higher even when diastolic pressure stays stable or drops. A 60-year-old with a systolic reading of 108 is in an excellent position cardiovascularly. It suggests their arteries have maintained good elasticity and that their heart isn’t working harder than it needs to.
For younger adults, both numbers carry roughly equal weight. At 108/70, neither number raises a flag in any age group.
Keeping Your Numbers in This Range
If you’re currently at 108/70, the goal is simply to stay there. The lifestyle habits that maintain healthy blood pressure are straightforward: regular physical activity (even brisk walking counts), a diet rich in fruits, vegetables, and whole grains with moderate sodium intake, maintaining a healthy weight, limiting alcohol, and managing stress. These aren’t just strategies for people with high blood pressure. They’re what keeps a normal reading normal over the decades when arterial stiffening would otherwise push numbers upward.