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Time to dust off that reusable water bottle.

Reviewed by Dietitian Jane Leverich, M.S., RDN

Key Points

• Staying adequately hydrated may help keep blood pressure levels healthy.
• Experts recommend carrying a reusable water bottle or setting reminders to increase hydration.
• A heart-healthy diet and regular physical activity may also support healthy blood pressure.

Hydration and blood pressure are closely linked. After all, your blood is made up mostly of water. “When you’re dehydrated, your blood volume and blood pressure decrease,” says Jacinta Anyaoku, M.D., DABOM. But not necessarily in a healthy way.

“When this happens, your body tries to compensate by constricting your blood vessels and retaining sodium to bring your blood pressure back up,” explains Anyaoku. Over time, repeated or chronic dehydration may place extra strain on the cardiovascular system and make it harder to maintain healthy blood pressure.

On the flip side, staying adequately hydrated can help keep blood pressure levels healthy as hydration can help your body maintain normal blood volume and support healthy circulation. Exactly how drinking more water affects your blood pressure depends on your hydration status and whether you’re experiencing dehydration, a temporary change in blood pressure or chronic hypertension.

To break it all down, we asked a physician and a registered dietitian to explain what happens to your blood pressure when you start drinking more water. Plus, they share strategies for supporting healthy blood pressure levels.

It May Help Support Normal Circulation

Drinking more water may help lower your blood pressure, especially if you’re chronically dehydrated. Dehydration leads to less water and more sodium in your blood. This triggers the release of a hormone called vasopressin, which works with your kidneys to try and retain water. Vasopressin also tightens and constricts blood vessels, increasing blood pressure. When you drink water, it can help reduce the spike in blood pressure, bringing levels back down.

“When you’re well hydrated, your body doesn’t need to activate that compensation response that occurs when you are dehydrated,” says Anyaoku. “This allows your blood vessels to be in a more relaxed state, which in turn lowers blood pressure.”

If you’re already well hydrated and your blood pressure is within a healthy range, drinking water helps your body maintain healthy blood pressure and normal circulation.

Your Risk of Hypertension May Decrease

Drinking enough water not only can lower blood pressure but may also reduce your risk of developing hypertension. “A large longitudinal study published in Frontiers in Public Health followed adults for 9 years and found that people who drank six or more cups of plain water daily had a lower risk of developing hypertension than those who drank one cup or less per day,” says Anyaoku. While more research is needed to understand the relationship between hydration and blood pressure, drinking enough water is a simple habit that may support overall cardiovascular health.

Nearly half of adults in the United States have hypertension, which is defined as a systolic blood pressure (SBP) above 130 mm Hg or a diastolic blood pressure (DBP) above 80 mm Hg. High blood pressure increases the risk for heart disease and stroke. Many factors, including genetics, diet, physical activity and lifestyle habits, contribute to hypertension. Some research suggests that people with hypertension tend to be less hydrated, which may be one reason hydration could play a role in supporting healthy blood pressure. “Long-term, increased fluid intake may help promote sodium excretion, which lowers blood pressure,” says Patricia Kolesa MS, RDN.

Your Blood Pressure May Temporarily Increase

While drinking more water generally supports healthy blood pressure, there are certain situations where it can temporarily raise blood pressure–and that can actually be beneficial. For example, some people experience a drop in blood pressure when standing up, which can cause dizziness or lightheadedness. While this can happen to anyone, it’s particularly severe in individuals with orthostatic hypotension. In this condition, SBP drops by 20 mm Hg or more and DBP drops by 10 mm Hg or more within three minutes of standing.

In these cases, quickly drinking 300-500 milliliters (about 2 cups) of water may help bring blood pressure back up. The same temporary effect can occur in healthy individuals, as rapidly drinking water can cause a slight increase in blood pressure.

This happens for two main reasons. First, drinking water increases blood volume, which can increase pressure within your blood vessels. Second, quickly gulping water stimulates the sympathetic nervous system–the body’s “fight-or-flight” response–which can create a cascade of events in the body that includes your blood vessels constricting, which increases blood pressure.

Tips to Stay Hydrated

Staying hydrated benefits health beyond blood pressure, but knowing you need to drink more water and actually doing it are two different things. Here are a few expert-backed ways to make hydration easier:

• More water-rich foods. Drinking water isn’t the only way to stay hydrated. Eating foods that have a high water content can help too. “Fruits and vegetables like watermelon, cucumbers, oranges and strawberries have a high water content,” says Anyaoku. “They also provide potassium and other nutrients that support healthy blood pressure,” she says.
• Carry a water bottle you enjoy using. “Make drinking water enjoyable by using a fancy glass or a fun water bottle,” says Kolesa. The trick is to actually keep your water bottle with you, so you can sip water throughout the day to avoid getting thirsty. “By the time you feel thirsty, your body is signaling that it is dehydrated,” says Anyaoku.
• Set reminders. If you tend to forget to drink water, set reminders on your phone or smartwatch every couple of hours. Small, consistent sips throughout the day are often easier than trying to catch up all at once.
• Replace electrolytes when needed. Electrolytes, like sodium, magnesium, potassium and calcium, help your body retain the fluid you consume. If you’re exercising for long periods, spending time in the heat or sweating heavily, an electrolyte-containing beverage may help replace minerals lost through sweat. However, if you have high blood pressure, pay attention to the sodium content. Some electrolyte drinks are high in sodium, so talk with your healthcare provider about what’s appropriate for you. Potassium- and magnesium-rich foods can also help support healthy blood pressure.

Other Tips to Support Blood Pressure

Drinking adequate water is only one way to support healthy blood pressure levels. Here are other ways to prevent hypertension and keep blood pressure within a healthy range.

• Follow the DASH diet. “The Dietary Approaches to Stop Hypertension (DASH) diet is the most effective dietary pattern for lowering blood pressure and can reduce systolic blood pressure by approximately 5–8 mm Hg in people with hypertension,” says Anyaoku., The eating pattern emphasizes fruits, vegetables, whole grains, low-fat dairy and lean proteins while limiting saturated fat and sodium.
• Move your body. Regular physical activity helps keep blood vessels healthy and supports normal blood pressure. Even if you don’t have time for a full workout, “a 10-15 minute walk each day helps blood vessels stay relaxed and reduces your heart’s resting workload,” says Anyaoku.
• Cook more meals at home. One sneaky sodium culprit is eating out. Restaurant meals, as well as many packaged foods, are high in salt. Cooking more at home can naturally reduce sodium intake, especially if you use methods like baking, grilling, air-frying, roasting and steaming, says Kolesa.
• Eat more potassium-rich foods: “Potassium counteracts sodium’s effects by helping excrete excess sodium through the urine and easing tension in the blood vessels,” says Kolesa. Potatoes, tomatoes, bananas, beans and oranges are some of the best sources of potassium.

Our Expert Take

Overall, drinking more water is one simple habit that can help support healthy blood pressure. By maintaining normal blood volume and circulation, drinking enough water helps your body regulate blood pressure and may even play a role in lowering the risk of hypertension over time. In certain situations—such as when blood pressure drops after standing up too quickly—drinking water can also temporarily raise blood pressure to help restore it to a healthier level. Whether you start carrying a reusable water bottle or set reminders to sip throughout the day, small habits can make staying hydrated easier.