How to Bring Down the Bottom Number of Blood Pressure

Lowering diastolic blood pressure, the bottom number in a blood pressure reading, relies on many of the same strategies used to lower the top number: eating less sodium, exercising regularly, losing excess weight, cutting back on alcohol, and managing stress. But diastolic pressure has its own quirks. It tends to be the dominant problem in younger adults, it responds especially well to certain types of exercise, and pushing it too low can create its own risks in people with heart disease. Understanding these details helps you target the bottom number more effectively.

Why the Bottom Number Deserves Attention

For years, the top number (systolic) got most of the clinical focus. But a large analysis of more than 1.3 million adults found that both systolic and diastolic hypertension independently predicted heart attacks, strokes, and other cardiovascular events, regardless of whether hypertension was defined at the older threshold of 140/90 or the newer 130/80.¹ An earlier pooled analysis of 45 prospective studies covering roughly 450,000 people showed a fivefold difference in stroke risk between those with the highest and lowest diastolic pressures, with the gap even wider in younger age groups.²

Elevated diastolic pressure also tends to fly under the radar. People whose systolic reading is normal but whose diastolic is high, a pattern called isolated diastolic hypertension, are less likely to know they have a problem compared to those whose top number is also elevated.³ That lack of awareness matters, because a recent study following nearly 24,000 adults for a median of 17 years found that isolated diastolic hypertension in young adults was associated with a 36% higher risk of atherosclerotic cardiovascular disease and a 69% higher risk of heart failure compared with normal blood pressure.⁴

Who Tends to Have a High Bottom Number

Isolated diastolic hypertension is overwhelmingly a younger person’s condition. In the United States, nearly half of untreated hypertensive adults under 50 have a diastolic reading above 90 while their systolic stays in the normal range. Among those under 40, the proportion climbs above 55%. The peak prevalence sits between ages 30 and 49, then drops steeply with age, becoming almost nonexistent in untreated older adults.³ This age pattern is driven by changes in blood vessels over time: in younger people, stiffer small arteries raise resistance against blood flow, pushing diastolic pressure up. As the large arteries stiffen with age, systolic pressure takes over, and diastolic actually tends to flatten or drop.⁵

That trajectory also means many younger adults with isolated diastolic hypertension do not stay in that category forever. In the long-term follow-up study mentioned earlier, about 30% of young adults with isolated diastolic hypertension still had it years later, while roughly 37% had progressed to combined systolic-diastolic hypertension.⁴ Catching and managing a high bottom number early can disrupt that progression.

Dietary Strategies

The DASH eating pattern, which emphasizes fruits, vegetables, whole grains, lean protein, and low-fat dairy while minimizing saturated fat and sweets, is one of the most studied dietary interventions for blood pressure. In the DASH-Sodium trial, combining the DASH diet with reduced sodium intake produced the largest blood pressure drops. Even among people who did not already have hypertension and who simply ate a standard diet but lowered their sodium, diastolic pressure fell by about 1.5 to nearly 4 points depending on age.⁶ For those with existing hypertension, the reductions were larger still.

Beyond the overall dietary pattern, nitrate-rich foods like beetroot, spinach, and arugula have attracted research interest. The body converts dietary nitrate into nitric oxide, which relaxes blood vessel walls. In a trial of hypertensive patients, daily beetroot juice supplementation for four weeks lowered clinic diastolic pressure by about 2.4 points on average and 24-hour ambulatory diastolic pressure by about 5 points, with no sign that the effect faded over the trial period. Arterial stiffness also improved.⁷ In older adults, nitrate supplementation similarly reduced resting diastolic pressure by a few points compared to placebo.⁸ These are modest changes individually, but they stack with other interventions.

Exercise, With a Surprising Standout

Aerobic exercise, the standard recommendation for blood pressure, works. Walking, cycling, or swimming for 30 or more minutes most days of the week will lower both numbers. But a systematic review and meta-analysis found that isometric resistance training, which involves holding a static muscle contraction like a wall sit or a sustained handgrip, lowered both systolic and diastolic pressure by a larger magnitude than traditional aerobic or dynamic resistance training.⁹ The typical protocols tested in trials used sessions of a few minutes, several times a week, making isometric training easy to fit into daily life. A wall sit held for two minutes, with a rest, repeated a few times, costs you about ten minutes.

The mechanism likely involves improved blood vessel function after the brief period of restricted blood flow during the contraction. Think of it like interval training for your arteries. Because the bottom number is especially sensitive to peripheral vascular resistance, the kind of vascular remodeling that isometric exercise promotes may be particularly relevant to diastolic pressure. That said, isometric training works best as an addition to aerobic exercise, not a replacement.

Losing Weight

Excess body weight is one of the strongest modifiable drivers of high blood pressure, and diastolic pressure responds to weight loss along with systolic. A meta-analysis of overweight and obese adults found that a moderate reduction in BMI (about 2.3 points, corresponding to roughly 15 or so pounds for many people) was associated with a diastolic drop of about 3.4 points. A larger BMI reduction of around 4 points was associated with a diastolic drop of about 3.6 points.¹⁰ The returns on diastolic pressure flatten out somewhat as weight loss increases, unlike systolic pressure, which kept falling more steeply with greater weight loss. Still, even moderate weight loss makes a meaningful dent.

Cutting Back on Alcohol

Alcohol raises blood pressure through multiple pathways, including activating the sympathetic nervous system and promoting fluid retention. A dose-response meta-analysis of intervention trials found that reducing alcohol intake lowered diastolic pressure by about 2 points on average across all trials, with the benefit scaling strongly to how much someone was drinking before they cut back. For every additional drink per day at baseline, the diastolic drop from reducing intake increased by about 0.75 points.¹¹ In practical terms, if you are a heavy drinker, cutting way back may be one of the single most effective things you can do for your bottom number. If you drink moderately, the benefit is smaller but still real.¹²

Treating Sleep Apnea

Obstructive sleep apnea, where the airway repeatedly collapses during sleep, triggers spikes in blood pressure throughout the night. The surges in sympathetic nervous system activity during each breathing interruption raise both numbers but are especially harmful overnight, a time when blood pressure should normally dip. Treating sleep apnea with continuous positive airway pressure (CPAP) consistently reduces nocturnal diastolic pressure. In patients with diabetes, chronic kidney disease, and resistant hypertension, therapeutic CPAP lowered awake diastolic pressure by about 5 points and sleep diastolic pressure by about 10 points compared with a sham device.¹³ CPAP also reduced the frequency of sudden blood pressure fluctuations during both REM and non-REM sleep.¹⁴

If you snore loudly, wake feeling unrefreshed, or have been told you stop breathing in your sleep, getting evaluated for sleep apnea may be a more productive path to lower diastolic pressure than adding yet another lifestyle tweak. An earlier placebo-controlled trial found that while CPAP clearly reduced nighttime blood pressure, the daytime benefit was harder to separate from a placebo effect, so the biggest gains appear to be overnight.¹⁵

Stress, Breathing, and the Sympathetic Nervous System

Chronic stress keeps the sympathetic nervous system, your fight-or-flight wiring, running hotter than it should, which tightens small arteries and pushes diastolic pressure up. Two approaches have decent evidence for dialing that back. Device-guided slow breathing, where you follow a pacing signal to breathe at about six breaths per minute, lowered diastolic pressure by about 3 points in a study of veterans with elevated blood pressure. The researchers also measured sympathetic nerve firing directly and found it dropped during the breathing sessions.¹⁶ Separately, a mindfulness-based stress reduction program improved blood pressure along with markers of stress and inflammation, with the proposed mechanism running through reduced cortisol levels and lower sympathetic activation.¹⁷

You do not need a device or a formal program to try slow breathing. Inhaling for about five seconds and exhaling for about five seconds for 10 to 15 minutes a day approximates the pace used in the research. The effect is acute, meaning your pressure dips during and shortly after the session. Whether that translates to sustained 24-hour reductions requires longer-term practice, but it is essentially free and risk-free.

When the Bottom Number Goes Too Low

This is where the story gets more nuanced. In people with coronary artery disease, a study found a J-shaped curve for diastolic pressure: the lowest risk of heart attacks and death sat around 84 mmHg, and the risk progressively increased as diastolic fell below that point.¹⁸ The heart muscle is unusual in that it fills with blood mostly during the relaxation phase of the heartbeat, when diastolic pressure is the driving force. Push diastolic too low and you may starve the heart of its own blood supply, especially if coronary arteries are already narrowed.

In frail older adults, the risk floor may be even higher. A study of elderly patients found a marked increase in adverse outcomes when diastolic pressure dropped below 60 mmHg, particularly when the gap between the top and bottom numbers (pulse pressure) was wide.¹⁹ This is why the goal is not to drive diastolic pressure as low as possible. If your bottom number is already in the 60s or lower and you have heart disease or are elderly, aggressive further reduction can do more harm than good. Talk to your doctor before stacking interventions aimed at lowering it further.

Medications and the Bottom Number

When lifestyle changes are not enough, several classes of blood pressure medication lower diastolic pressure. A large analysis of 354 randomized trials found that the major drug classes, including ACE inhibitors, ARBs, calcium channel blockers, beta-blockers, and thiazide diuretics, produced remarkably similar reductions in both systolic and diastolic blood pressure at standard doses. Using half the standard dose still achieved about 80% of the blood pressure reduction with fewer side effects.²⁰ Because no single drug class is dramatically better at targeting the bottom number specifically, your doctor will usually choose based on your other health conditions and how well you tolerate side effects.

One important consideration: if your blood pressure is being treated and the top number is well controlled but the bottom number remains high, that is worth mentioning to your doctor. Conversely, if treatment is pulling the bottom number into the low 60s while your systolic is still elevated, the J-curve risk discussed above comes into play, and your regimen may need adjustment.

How Age Changes the Equation

A French longitudinal study tracking people over nine years showed that diastolic blood pressure tends to rise until about age 50 and then decline, while systolic pressure keeps climbing.²¹ The crossover happens because large arteries stiffen with age, which amplifies the top number while the bottom number loses some of its hydraulic support. People with metabolic syndrome see this shift happen earlier and more dramatically.

For people over 60, an elevated diastolic reading sometimes reflects measurement artifact rather than true vascular pressure. Stiff arteries resist compression by the blood pressure cuff, which can falsely inflate the diastolic reading.¹⁹ If you are older and your bottom number seems stubbornly elevated despite treatment, it is worth asking whether the reading is accurate. Ambulatory monitoring over 24 hours can help sort this out.

Measurement Errors That Mimic a High Bottom Number

Before overhauling your lifestyle based on a single reading, make sure the reading is trustworthy. One of the most common sources of error is cuff size. A randomized crossover trial found that using a regular-sized cuff on someone who actually needed a large or extra-large cuff inflated the diastolic reading by about 1.8 points when the cuff was one size too small and by about 7.4 points when it was two sizes too small.²² A 7-point diastolic error could easily push a normal reading into the hypertensive range. If your arm circumference is above about 13 inches, ask your provider whether the cuff they are using is correct. Home monitors come with standard cuffs that do not fit everyone.

Other common pitfalls include measuring right after caffeine or exercise, crossing your legs during the reading, talking, resting your arm above or below heart level, or using a wrist monitor inconsistently. All of these can nudge the bottom number by a few points in either direction.

Nighttime Blood Pressure Patterns

Blood pressure normally drops by about 10 to 20% during sleep, a pattern called dipping. When that overnight drop does not happen, called non-dipping, the risk of cardiovascular events rises independently of your average 24-hour blood pressure.²³ Studies with follow-up periods ranging from six to 21 years have consistently found that non-dippers face roughly double the cardiovascular risk even after accounting for other health conditions.²⁴

Non-dipping is more common in people with sleep apnea, chronic kidney disease, diabetes, and high salt intake. If your office blood pressure is borderline but you suspect your overnight numbers are not behaving, 24-hour ambulatory monitoring is the only way to know for sure. Treating the underlying cause of non-dipping, whether that is sleep apnea, excessive sodium, or medication timing, can restore the normal overnight drop in both the top and bottom numbers.

Air Pollution and Diastolic Pressure

This one surprises most people. Breathing fine particulate matter, the kind found in traffic exhaust and wildfire smoke, acutely raises diastolic blood pressure. In a controlled exposure study in Toronto, diastolic pressure rose by about 3 to 4 points during exposures containing fine particles, and the researchers pinpointed the mechanism as an imbalance in autonomic nervous system activity, essentially the same sympathetic overdrive that stress causes.²⁵ Animal studies have confirmed that the blood pressure rise from particle inhalation is driven by increased peripheral vascular resistance, directly affecting the bottom number.²⁶

Over longer periods, living in areas with high ambient particulate matter is linked to chronically elevated blood pressure through a combination of systemic inflammation, oxidative stress, and vascular remodeling.²⁷ You cannot control the air outside, but using HEPA filters indoors, exercising away from busy roads, and checking air quality indexes before outdoor workouts can reduce your exposure during the worst days.

When a Hidden Cause Is Keeping It High

If your bottom number stays elevated despite consistent lifestyle changes and medications, your doctor may investigate secondary causes. One of the most common and underdiagnosed is primary aldosteronism, where the adrenal glands overproduce the hormone aldosterone, causing the body to retain sodium and water. A meta-analysis estimated that about 4% of hypertensive patients in primary care have this condition, rising to roughly 9% of those referred to hypertension specialists, and potentially 15 to 20% of patients with treatment-resistant hypertension. A simple blood test measuring the ratio of aldosterone to renin can screen for it, and treatment, either with specific medications or sometimes surgery, can resolve the hypertension entirely.

Other secondary causes worth ruling out include thyroid disorders, kidney artery narrowing, and certain medications like nonsteroidal anti-inflammatory drugs, decongestants, and some antidepressants that raise diastolic pressure as a side effect. If you have been diligently managing diet, exercise, weight, alcohol, and stress and the bottom number still will not budge, the answer may not be trying harder but looking deeper.