Raising a low diastolic blood pressure, the bottom number in your reading, starts with identifying why it’s low in the first place. A diastolic reading below 60 mmHg is generally considered low, and the fix depends heavily on the cause. For some people, simple changes like drinking more water or adjusting medications can make a meaningful difference. For others, a low diastolic number reflects structural changes in the arteries that require a different approach entirely.
Why Diastolic Pressure Matters
Diastolic pressure measures the force in your arteries between heartbeats, when your heart is resting and refilling with blood. This is also when your heart muscle itself gets most of its oxygen supply. The coronary arteries that feed your heart rely on adequate diastolic pressure to push blood through them. When diastolic pressure drops too low, it can reduce blood flow to the heart muscle, potentially causing subtle damage over time. This effect is even more pronounced in people who already have narrowed coronary arteries.
That said, not every low diastolic reading is dangerous. In younger, healthy people, a diastolic number in the 50s with no symptoms is often normal. The concern grows when diastolic pressure drops below 60 and you experience dizziness, fatigue, lightheadedness, or fainting.
Common Causes of Low Diastolic Pressure
The most straightforward cause is dehydration. When your body doesn’t have enough fluid, total blood volume drops, and blood pressure falls with it. Fever, vomiting, diarrhea, heavy sweating, and overuse of diuretics can all push you into dehydration without you realizing it.
Medications are another major factor. Blood pressure drugs, particularly calcium channel blockers, have been linked to lower diastolic readings and wider pulse pressure (a bigger gap between your top and bottom numbers). Beta-blockers, diuretics, and ACE inhibitors can also contribute. If your diastolic pressure started dropping after a medication change, that’s worth flagging to your prescriber.
In older adults, arterial stiffness is one of the most common reasons for a low diastolic number. As arteries lose their elasticity with age, they can’t recoil between heartbeats to maintain pressure. This produces a pattern called isolated systolic hypertension: the top number goes up while the bottom number drops. This type of low diastolic pressure reflects underlying vascular disease rather than a simple fluid deficit, and it won’t respond to the same lifestyle fixes.
Other causes include heart valve problems, a slow heart rate (bradycardia), hormone conditions like Addison’s disease, low blood sugar, and conditions affecting the autonomic nervous system.
Drink Water, and Drink It Quickly
Rapid water intake is one of the most effective and immediate ways to raise blood pressure. Research published in Circulation found that drinking about 480 mL (roughly 16 ounces, or two standard glasses) of water produced a significant pressor response. In people with autonomic disorders, diastolic pressure rose by 14 to 16 mmHg. Even in healthy older adults, systolic pressure increased by about 11 mmHg.
The key detail: the effect kicks in within 5 minutes, peaks around 30 to 35 minutes after drinking, and lasts over an hour. Drinking water in a bolus (all at once, rather than sipping slowly) appears to trigger a reflex through the sympathetic nervous system rather than simply expanding blood volume. Plasma volume, in fact, didn’t change in the study, meaning the response is neurological, not just hydraulic. This makes rapid water drinking a practical first-line strategy, especially before situations where you know your pressure tends to drop, like standing for long periods or after meals.
Increase Your Salt Intake Carefully
Sodium helps your body retain fluid, which supports blood volume and blood pressure. If your diastolic pressure is low because of dehydration or insufficient fluid retention, modestly increasing your salt intake can help. Adding salt to meals, choosing salted snacks, or drinking an electrolyte beverage are simple starting points.
This approach works best for people whose low pressure stems from fluid-related causes. It’s not appropriate for everyone, particularly if you also have kidney disease, heart failure, or high systolic pressure. The goal isn’t to eat as much salt as possible but to ensure you’re not inadvertently restricting sodium when your body needs it.
Abdominal Compression Over Stockings
Compression garments are a common recommendation for low blood pressure, but not all compression is equally effective. A review published in Neurology compared different nonpharmacologic interventions and found that thigh-high compression stockings (at 23 to 32 mmHg pressure) were the least effective option, helping only about 32% of participants and producing minimal improvement in blood pressure readings. The researchers went so far as to suggest stockings should be “disregarded” for older adults with low blood pressure.
Abdominal compression, on the other hand, performed significantly better. It was effective in about 52% of participants and improved standing systolic pressure by an average of 10 mmHg. Abdominal binders work by preventing blood from pooling in the large vascular bed of the abdomen when you stand. If you’ve been wearing knee-high or thigh-high stockings with little benefit, switching to an abdominal compression garment may be worth trying.
Other Practical Strategies
Eating smaller, more frequent meals can help if your blood pressure tends to drop after eating. Postprandial hypotension, a blood pressure drop that occurs one to two hours after a meal, is especially common in older adults. Large meals divert more blood to the digestive system, pulling it away from the rest of your circulation. Smaller portions reduce this effect.
Changing positions slowly gives your body time to adjust. When you go from lying down to standing, blood naturally shifts toward your legs. Your nervous system compensates by tightening blood vessels and increasing heart rate, but this reflex can be sluggish in some people. Sitting on the edge of the bed for 30 seconds before standing, or flexing your calf muscles before getting up, gives your cardiovascular system a head start.
Regular physical activity, particularly exercises that strengthen your legs, can improve the muscle pump that helps push blood back toward your heart. Even moderate walking improves vascular tone over time. Avoiding prolonged standing in one position also helps prevent blood from pooling in the lower body.
When Low Diastolic Pressure Signals Something Bigger
If your low diastolic pressure comes with a high systolic number, the issue is likely arterial stiffness rather than low blood volume. This pattern is common after age 60 and represents a cardiovascular risk in its own right. In this scenario, trying to raise the diastolic number through salt and water may inadvertently push the systolic number even higher. Treatment focuses on managing the arterial stiffness and overall cardiovascular risk rather than targeting the diastolic number alone.
Low diastolic pressure can also be a sign of heart valve problems (particularly aortic regurgitation, where the valve doesn’t close fully and blood leaks backward), thyroid disorders, or severe infections. If your diastolic pressure is consistently below 60 and you’re experiencing symptoms like persistent fatigue, chest discomfort, or frequent lightheadedness, these underlying conditions need to be investigated rather than masked with lifestyle adjustments.
For people currently taking blood pressure medications who notice their diastolic reading dropping into the low 50s or below, a medication adjustment may be the most effective intervention. This is especially relevant with calcium channel blockers, which have been specifically associated with lower diastolic pressures and wider pulse pressure in some populations.