A reading of 108/64 mmHg falls squarely within the normal blood pressure range and, for most people, reflects healthy cardiovascular function. Current guidelines from the American College of Cardiology and American Heart Association define normal blood pressure as anything below 120/80 mmHg, and 108/64 sits comfortably under both thresholds. But whether that number is genuinely “good” for you depends on context: your age, fitness level, symptoms, and how the reading was taken all shape what it means in practice.
Where 108/64 Sits on the Classification Scale
The ACC/AHA framework breaks blood pressure into clear tiers: normal is below 120/80, elevated is a systolic (top number) of 120–129 with a diastolic (bottom number) still under 80, Stage 1 hypertension is 130–139 systolic or 80–89 diastolic, and Stage 2 hypertension starts at 140 systolic or 90 diastolic.1Peertechz Publications. Revising blood pressure classification guidelines: A call for normal lower limits in the “American college of cardiology/American heart association task force on clinical practice guidelines for hypertension” – Section: Current blood pressure classification guidelines At 108/64, both numbers fall well below the normal ceiling. Some clinicians have proposed that normal should also have a lower boundary, defining it as 90–119 systolic and 60–79 diastolic. Under that revised definition, 108/64 still qualifies as normal with room to spare on both ends.
What these guidelines do not do is distinguish between “good” and “merely acceptable” within the normal range. A reading of 118/78 and a reading of 100/62 are both classified identically as normal, even though the latter reflects a meaningfully lower resting pressure. That distinction matters when you are trying to figure out whether your number is something to celebrate or something to watch.
Why Low-Normal Blood Pressure Is Usually a Good Sign
Long-term data consistently show that people with lower blood pressure in the normal range live longer and stay healthier. A study tracking men over 48 years found a graded relationship between blood pressure and total mortality: those with normal blood pressure at midlife had the lowest death rates, with an average survival advantage of more than seven years compared to those with Stage 2 hypertension and nearly a year compared to those in the prehypertension range.2PubMed. Low midlife blood pressure, survival, comorbidity, and health-related quality of life in old age: the Helsinki Businessmen Study Lower midlife blood pressure was also associated with better physical functioning and self-rated health decades later.
For a healthy adult without symptoms, 108/64 is not just normal; it is the kind of reading that tracks with good long-term outcomes. Your heart is not working as hard to push blood through your vessels, your arteries are under less stress, and your risk of the damage that accumulates over years of elevated pressure is lower.
When a Diastolic of 64 Deserves a Closer Look
The diastolic number in 108/64 is worth thinking about separately. While 64 is perfectly normal for most people, diastolic pressure below 60 mmHg has been linked to increased cardiovascular risk in certain populations. A large study found that diastolic blood pressure under 60 mmHg was associated with roughly a 50% higher risk of coronary heart disease and a 30% higher risk of death compared to a diastolic in the 80–89 range. That association was strongest in people who also had a systolic reading above 120.3PubMed Central. Diastolic blood pressure, subclinical myocardial damage, and cardiac events: Implications for blood pressure control The concern is that very low diastolic pressure can reduce blood flow to the heart muscle itself, since coronary arteries fill mainly during the relaxation phase of each heartbeat.
At 64, you are above that threshold and not in concerning territory. But if you have been told your diastolic tends to run in the low 60s and occasionally dips into the 50s, and especially if you have any underlying heart disease, it is worth mentioning to your doctor. The risk is not about occasional dips; it is about sustained low diastolic pressure in people whose hearts already have compromised blood supply.
The Pulse Pressure Angle
Pulse pressure, the difference between your systolic and diastolic numbers, also tells a story. For 108/64, your pulse pressure is 44 mmHg. Research on healthy adults across different age groups found that the average pulse pressure was about 43 mmHg, increasing after age 40, with some sex-based differences emerging after age 50.4PubMed Central. The optimal pulse pressures for healthy adults with different ages and sexes correlate with cardiovascular health metrics A pulse pressure of 44 is right in that healthy range. A very wide pulse pressure (say, above 60) can signal stiffening arteries, while a very narrow one (below 25) can suggest reduced heart output. Yours is unremarkable in the best sense.
Athletes and Fit Individuals Often Land Here
If you exercise regularly, a reading of 108/64 might be partly a reflection of your cardiovascular fitness. Research comparing young athletes and non-athletes has found that both endurance and non-endurance athletes tend to have lower diastolic blood pressure than people who do not train.5PubMed Central. Resting Electrocardiogram and Blood Pressure in Young Endurance and Nonendurance Athletes and Nonathletes Endurance-trained athletes specifically tend to run lower overall: one systematic review found average readings around 119/72 in endurance athletes compared to about 131/77 in strength-trained athletes.6British Journal of Sports Medicine. Blood pressure and hypertension in athletes: a systematic review
Regular aerobic exercise makes the heart more efficient at pumping blood and improves arterial flexibility, both of which lower resting pressure. If you are someone who runs, cycles, swims, or does similar activity several times a week, 108/64 is entirely expected and nothing to worry about. Even moderately active people can see their resting blood pressure settle in this range.
Blood Pressure During Pregnancy
Pregnant women commonly see their blood pressure drop during the first and second trimesters. A meta-analysis of normal pregnancies found that systolic blood pressure was lowest at around 10 weeks of gestation, averaging about 110 mmHg, while diastolic pressure hit its lowest point around 21 weeks at roughly 66 mmHg. Both then climbed gradually through the third trimester, reaching about 116/73 by week 40.7PubMed Central. Trends of blood pressure and heart rate in normal pregnancies: a systematic review and meta-analysis
A reading of 108/64 in the first or second trimester is right in line with these physiological changes. Blood volume increases substantially during pregnancy, and blood vessels dilate to accommodate it, which naturally lowers pressure. If you are pregnant and seeing numbers like this, your care provider is likely unconcerned unless you are experiencing dizziness, fainting, or other symptoms. What they watch for more carefully is pressure that climbs steeply later in pregnancy, which can signal preeclampsia.
Symptoms Are What Separate Normal from Too Low
There is no universally agreed-upon threshold where “normal” becomes “low blood pressure” in a clinical sense. Most doctors treat hypotension as a symptomatic diagnosis: if your numbers are low and you feel fine, the numbers are not a problem. If you are dizzy, lightheaded, fatigued, having trouble concentrating, or blacking out when you stand up, then even a blood pressure that looks acceptable on paper needs attention.
In a large heart failure trial, roughly 16% of patients experienced low blood pressure without any symptoms, while about 11% experienced it with symptoms like dizziness or fainting. Patients with symptomatic hypotension tended to be older and have more cardiovascular conditions.8PubMed. Asymptomatic vs Symptomatic Hypotension With Sacubitril/Valsartan in Heart Failure and Reduced Ejection Fraction in PARADIGM-HF That study was specifically in people taking heart failure medication, but the principle holds more broadly: the clinical relevance of a low reading depends heavily on whether the person is feeling the effects of it.
For someone reading 108/64 and feeling well, these numbers are not a signal to seek treatment. But if you are getting lightheaded every time you stand up from the couch, or nearly fainting in the shower, those symptoms are worth reporting regardless of what your specific numbers say.
What Medications Can Do to Your Numbers
If you take blood pressure-lowering medication for hypertension, heart failure, or another cardiovascular condition, 108/64 might reflect your treated blood pressure rather than your natural resting level. A pooled analysis of two large clinical trials found that patients whose treated systolic pressure dropped below 120 mmHg had increased risks of cardiovascular death and all-cause death compared to those maintained in the 120–140 range. A treated diastolic below 70 mmHg was associated with higher risk of heart attack and hospital admission for heart failure.9The Lancet. Effects of low blood pressure on cardiovascular events among patients with coronary artery disease and high vascular risk: a pooled analysis of the ONTARGET and TRANSCEND trials
This does not mean 108/64 is dangerous on medication. The risk depends on your starting point, your specific conditions, and what the medication is doing. But it does mean that the “lower is always better” intuition breaks down in patients on treatment. The lowest risk in those trials clustered around a systolic of 130 and a diastolic near 75. If your doctor has you on antihypertensive medications and you are consistently reading 108/64, it is reasonable to mention it at your next visit, especially if you have coronary artery disease. Your dose may need adjusting.
Your Reading Fluctuates More Than You Think
A single reading of 108/64 is a snapshot, not a portrait. Blood pressure follows a circadian rhythm: it peaks during the daytime and drops during sleep. Research has found that even when people stay in bed around the clock, systolic pressure still drops by about 8 mmHg and diastolic by about 4 mmHg at night, suggesting that the body’s internal clock drives much of this cycle independently of physical activity.10PubMed Central. Day/night variability in blood pressure: influence of posture and physical activity The morning surge when you wake and become upright adds to the daytime peak.
Even body weight plays a role in how pronounced this daily rhythm is. Obese individuals, even those with normal average blood pressure, may show blunted nighttime dipping, with higher pressure during sleep and more variable readings during the day.11Journal of Rare Cardiovascular Diseases. Impact of Body Mass Index on Ambulatory Blood Pressure and Circadian Rhythm Patterns
Eating a meal can also transiently lower your blood pressure. In healthy adults, diastolic blood pressure dropped by about 8% within 45 minutes of eating, with central blood pressure showing similar declines.12The American Journal of Clinical Nutrition. Acute effects of food on postprandial blood pressure and measures of arterial stiffness in healthy humans The effect comes from blood being redirected to the digestive tract, causing blood vessels there to dilate and total resistance through the body to fall.13The American Journal of Cardiology. Postprandial alterations in hemodynamics and blood pressure in normal subjects In older adults, this postprandial dip can be more severe, sometimes dropping systolic pressure enough to cause dizziness or fainting, especially after carbohydrate-heavy meals.14PubMed Central. Postprandial Hypotension: An Underreported Silent Killer in the Aged If your 108/64 was taken shortly after eating, your resting baseline might actually be a few points higher.
How Measurement Technique Skews the Number
The conditions under which your blood pressure was measured matter more than most people realize. Clinical protocols call for sitting in a chair with feet flat on the floor, arm supported at heart level, after at least five minutes of quiet rest. One study of standardized measurements had participants empty their bladder and then rest for five minutes before three sequential readings were taken.15JAMA Internal Medicine. Effects of Cuff Size on the Accuracy of Blood Pressure Readings: The Cuff SZ Randomized Crossover Trial
In reality, blood pressure is often taken hastily at the end of a clinic visit, with the patient sitting on an exam table rather than in a proper chair. A study comparing positions in patients with high blood pressure found that readings taken while seated on a bed overestimated systolic pressure by about 5 mmHg compared to the recommended seated-in-a-chair method.16American Journal of Hypertension. What is the accuracy of clinic blood pressure measurement? If your 108/64 was taken informally, sitting on an exam table with your feet dangling, or right after walking briskly to the appointment, the true resting number could be somewhat different. Home blood pressure monitors, used consistently in the morning before eating or exercising, often give a more reliable picture of your typical levels.
Hydration, Heat, and Other Transient Influences
Dehydration is commonly listed as a cause of low blood pressure, and there is truth to it, but the picture is more nuanced than popular advice suggests. During exercise in the heat, dehydration clearly lowers blood pressure: one study found that mean arterial pressure dropped by about 6 mmHg during upright exercise when participants were dehydrated.17PubMed. Supine exercise restores arterial blood pressure and skin blood flow despite dehydration and hyperthermia But at rest and in normal conditions, the effect is less dramatic. A study that had healthy young adults gradually reduce their water intake over three days found no significant change in blood pressure variability or baroreflex function despite measurably increased blood concentration markers.18PubMed Central. Short-term water deprivation does not increase blood pressure variability or impair neurovascular function in healthy young adults
A separate study did find that mild dehydration was associated with a modest drop in central systolic blood pressure, though not in diastolic pressure or arterial stiffness.19PubMed. Effects of dehydration on central blood pressure in young healthy adults So if you had your blood pressure taken on a hot day after skipping water, the systolic number might read a few points lower than usual. But for a reading of 108/64 at a routine visit, dehydration is unlikely to be the main story.
Standing Up and the Orthostatic Question
One specific pattern to be aware of is orthostatic hypotension, where blood pressure drops sharply when you move from lying down or sitting to standing. Gravity pulls blood toward your legs, and your body normally compensates within seconds by tightening blood vessels and speeding up your heart rate. When that reflex is sluggish, you feel dizzy or see stars.
Research on older adults found distinct patterns in how blood pressure responded to standing: some people had a small, quick dip that recovered immediately, while others had a large drop that failed to recover. The group with large, non-recovering drops had the highest rates of orthostatic intolerance, with nearly 45% reporting symptoms, compared to about 18% in the small-drop group.20PubMed Central. Continuous noninvasive orthostatic blood pressure measurements and their relationship with orthostatic intolerance, falls, and frailty in older people If your sitting blood pressure is 108/64 and you are prone to dizziness when standing, it is worth having your doctor check for orthostatic changes by measuring your pressure in both positions.
Dietary Patterns and Resting Blood Pressure
If you are curious about why your blood pressure tends to be on the lower side of normal, your diet may be part of the explanation. Plant-heavy diets have been shown in randomized trials to lower blood pressure through several overlapping mechanisms: lower calorie intake that promotes healthy weight, higher potassium, lower sodium, increased availability of nitric oxide (which relaxes blood vessel walls), and favorable shifts in gut bacteria.21PubMed Central. Plant-Based Diets and Hypertension The DASH diet, specifically designed to lower blood pressure through increased fruits, vegetables, and low-fat dairy, shows even stronger effects when combined with sodium restriction.22PubMed Central. Plant-Based Diets Reduce Blood Pressure: A Systematic Review of Recent Evidence – Section: DASH Diet
None of this means you need to change your diet to “fix” a reading of 108/64. If anything, this reading suggests that whatever you are eating is working for your cardiovascular system. The dietary context is more useful for people who are borderline elevated and want to understand what might nudge their numbers down into this range naturally.
The J-Curve in Stroke Survivors and High-Risk Patients
One area where a reading near 108/64 warrants genuine attention is among people who have already had a stroke or have significant cardiovascular disease. A study of stroke survivors tracked recurrence at different systolic levels within the “normal” range. The lowest recurrence of stroke sat in the high-normal group, with a systolic around 130–140. But the very low-normal group, with systolic pressure under roughly 120, actually had higher all-cause mortality and vascular death rates than the high-normal group.23JAMA. Level of Systolic Blood Pressure Within the Normal Range and Risk of Recurrent Stroke
This U-shaped (or J-shaped) relationship, where risk increases at both high and very low pressures, has been observed in multiple studies of high-risk populations. It does not apply to healthy adults without cardiovascular disease. If you are 35 and otherwise well, a systolic of 108 is protective. If you are 72 with a history of stroke and coronary artery disease, that same number may be part of a more complex clinical picture that your cardiologist should be evaluating in the context of your full health history and any medications you are taking.