A blood pressure of 108/77 is a good reading. It falls squarely within the normal range, which the American Heart Association and American College of Cardiology define as a systolic (top number) below 120 mmHg and a diastolic (bottom number) below 80 mmHg. Both of your numbers clear those thresholds with comfortable room to spare.
Where 108/77 Falls on the Scale
Current guidelines break blood pressure into several categories for adults:
- Normal: systolic below 120 and diastolic below 80
- Elevated: systolic 120 to 129 and diastolic below 80
- Stage 1 hypertension: systolic 130 to 139 or diastolic 80 to 89
- Stage 2 hypertension: systolic 140 or higher, or diastolic 90 or higher
- Hypertensive crisis: systolic above 180 and/or diastolic above 120
At 108/77, you’re in the normal category. Your systolic number sits 12 points below the elevated threshold, and your diastolic number is just 3 points under the 80 cutoff that marks the beginning of high blood pressure territory. These same categories apply regardless of age. The guidelines do not use different thresholds for younger versus older adults.
How This Reading Affects Heart Health
A systolic reading in the low 100s is associated with low cardiovascular risk. A large study tracking cardiovascular events across different blood pressure ranges found that people with systolic readings between 100 and 109 mmHg had about 2.15 cardiovascular events per 1,000 person-years, compared to 3.80 events per 1,000 person-years for those in the 120 to 129 range. In other words, a systolic pressure in your range carried roughly half the event rate of someone closer to the upper edge of “normal.”
The same study found that any systolic pressure between 90 and 129 mmHg was not associated with increased cardiovascular risk in healthy people. So while lower readings within the normal range showed slightly fewer events in raw numbers, the differences were not statistically significant once other risk factors were accounted for. The takeaway: 108 is a healthy place to be, and current guidelines encourage most adults to achieve readings below 120/80 when possible.
Your Diastolic Number Is Fine Too
The bottom number, 77, reflects the pressure in your arteries between heartbeats. A diastolic reading becomes a concern when it consistently hits 80 or above while the systolic stays under 130, a condition called isolated diastolic hypertension. At 77, you’re below that line. There’s nothing to flag here.
Is It Too Low?
No. Low blood pressure, or hypotension, is generally defined as a reading below 90/60 mmHg. Your 108/77 is well above both of those cutoffs. Blood pressure only becomes a problem on the low end when it causes symptoms like dizziness, lightheadedness, or fainting. A drop of just 20 points in systolic pressure, for example from 110 down to 90, can be enough to trigger those symptoms. But a stable reading of 108 is not low blood pressure by any clinical measure.
If you do feel dizzy when standing up quickly or notice unusual fatigue, that’s worth mentioning to your doctor regardless of what the numbers say. The reading itself, though, is not concerning.
Why Some People Run Lower
Certain people tend to have blood pressure readings in the low-normal range naturally. Regular exercise is one of the most common reasons. Research on young athletes found that both endurance and non-endurance athletes had lower resting diastolic blood pressure than non-athletes. Among endurance athletes specifically, systolic readings ranged from 88 to 145 mmHg and diastolic readings from 45 to 82 mmHg at rest. A reading of 108/77 fits comfortably in that range.
Body size, genetics, and hydration status also play a role. Smaller or leaner individuals often have naturally lower blood pressure. None of these factors make the reading less healthy. If anything, they reinforce that your cardiovascular system is working efficiently.
During Pregnancy
If you’re pregnant and checking whether 108/77 is safe, the answer is yes. Normal blood pressure during pregnancy is defined the same way: below 120/80. Gestational hypertension isn’t diagnosed unless systolic reaches 140 or higher, or diastolic hits 90 or higher. Your reading is far from either threshold.
Blood pressure naturally fluctuates during pregnancy, often dipping in the second trimester before rising again closer to delivery. A reading of 108/77 during any trimester is reassuring.
What to Do With This Reading
There’s nothing you need to change. A blood pressure of 108/77 puts you in the range that guidelines actively encourage adults to reach. The practical move is simply to maintain the habits that got you here: staying active, keeping sodium intake reasonable, managing stress, and maintaining a healthy weight. Checking your blood pressure periodically, even once or twice a year, is enough to catch any upward trends early.