Sleep and Blood Pressure: Lower Your Risk and Get Quality Sleep
Key Takeaways
- High blood pressure, or hypertension, occurs when blood flows too forcefully through the blood vessels (arteries and veins) for too long, damaging the arteries and, eventually, other organs.
- Almost 50% of U.S. adults have high blood pressure, which happens when blood pressure readings go higher than 130/80 millimeters of mercury (mmHg).
- Sleep deprivation, defined by consistently getting fewer than seven hours of sleep in a 24-hour period, affects one in three U.S. adults.
- Blood pressure decreases by 10%–20% during healthy sleep, known as nocturnal dipping.
- Having hypertension puts you at risk for cardiovascular diseases and stroke, the leading causes of adult death in the United States.
Blood vessels are made up of arteries, veins, and capillaries and carry blood throughout your body before returning it to your heart. Your heartbeat creates pressure in the vessels each time it pumps blood into them. This pressure is necessary for blood to travel to every part of your body.
But when this pressure is too high in the blood vessels, it can cause problems. Most notably, consistently high blood pressure can cause tears in the arterial walls, which can then lead to buildup of plaque, narrowing of the arteries, decreased blood flow, blood clots, stroke, and vascular dementia (dementia caused by a series of strokes).
Not getting enough quality sleep can increase your chances of high blood pressure since sleep allows the heart to slow down and decrease the pressure on the blood vessels. According to the American Heart Association, high blood pressure is defined as being more than 130/80 millimeters of mercury (mmHg). During sleep, blood pressure drops by 10%–20% (to around 110/65 to 120/70, depending on daytime blood pressure). Good sleep is so important that the American Heart Association added getting quality sleep to its “Life’s Essential 8,” which are eight key measures for improving and maintaining cardiovascular health.
What is high blood pressure?
Blood pressure is measured by two numbers: systolic and diastolic. The two numbers are separated by a slash, with the systolic number on top of the slash and the diastolic number on bottom, such as “120/80.”
“The systolic, or the top number, is the maximum pressure of the blood against the arterial wall during the contraction phase of the heart, or when the heart is beating,” said Brynna Connor, MD, a family medicine practitioner and health care ambassador at NorthWestPharmacy.com in British Columbia, Canada. “The diastolic, or bottom number, is the minimum pressure, or force, of the blood during the relaxation phase of the heart.”
When the force of blood against the vessel walls is too high, it’s known as high blood pressure or hypertension.
Your blood pressure can range from normal to critically high. Here’s a breakdown:
- Normal blood pressure: A systolic reading of 120 mmHg or less and a diastolic of 80 mmHg or less
- Elevated blood pressure: A systolic reading of 120–129 mmHg and a diastolic of 80 mmHg or less
- Stage 1 hypertension: A systolic reading of 130–139 mmHg and a diastolic of 80–89 mmHg.
- Stage 2 hypertension: A systolic reading of 140 mmHg or higher and a diastolic of 90 mmHg or higher.
- Hypertensive crisis: A blood pressure reading is higher than 180/120 mmHg. Contact your health care provider right away for immediate care.
Either the systolic or diastolic numbers can be used when diagnosing high blood pressure, but an elevated systolic is more concerning for your health, particularly if you’re over age 50. The American Heart Association reports nearly 50% of adults in the United States are living with high blood pressure.
What are the causes of high blood pressure?
High blood pressure can be caused by several different factors—some you can control and others you can’t. These include:
- Family history: You are more likely to experience high blood pressure if a close family member, such as a parent or sibling, also has it.
- Age: According to Connor, arteries naturally lose some of their elasticity and become stiffer as we age, reducing their ability to expand and contract. This stiffening, along with any damage caused by tearing in the arterial walls, can lead to a dangerous buildup of cholesterol plaque within the arteries. This can cause hardening of the arteries, which decreases the blood’s ability to flow freely through the blood vessels and further increases blood pressure.
- Race: People of African descent have higher rates of high blood pressure compared to people of European descent. Black people are also more likely to have uncontrolled high blood pressure.
- Being at a higher weight: “Obesity is a major risk factor for high blood pressure,” said Alexander Dydyk, DO, a pain management physician at HealthyU Clinics in Arizona. But he added that you can have high blood pressure without being overweight, just as you can be overweight and not have high blood pressure.
- Diabetes: Diabetes can cause the blood vessels to become stiff, which can increase blood pressure.
- Smoking: Smoking tobacco products can speed plaque buildup in the arterial walls and has been strongly linked to hypertension and other coronary risks.
- Sleep apnea: If you have sleep apnea, or disordered breathing, you can experience dips in your blood oxygen levels while sleeping, which can raise your blood pressure.
- Inactivity: Studies have linked a lack of physical activity with a higher risk of hypertension.
- Not getting enough sleep: If you’re waking too frequently, having breathing disorders that disrupt your sleep, or are unable to fall or stay asleep, your blood pressure can’t decrease at night as it should, putting you at risk for hypertension.
What are the risks of hypertension?
Hypertension is known as the “the silent killer.” This sounds grim, but it’s because so many people who have high blood pressure don’t realize it until they’re having a health emergency. Unless you have dangerously high blood pressure levels, you may not have any symptoms. Some people do experience outward symptoms when their blood pressure is very high, like headaches, nosebleeds, or a pounding heartbeat.
Hypertension needs to be treated before it causes serious health issues. According to the Centers for Disease Control and Prevention (CDC), hypertension can lead to heart disease and stroke, which are both leading causes of adult death in the United States. It can also cause other health conditions, like:
- Heart attack: This occurs when blood flow to the heart muscle becomes blocked—usually due to cholesterol buildup in the arteries.
- Stroke: Also known as a “brain attack,” a stroke occurs when blood flow and oxygen to the brain are cut off by a blood clot or build-up of plaque in one of the brain’s blood vessels (ischemic stroke). A stroke can also happen when a blood vessel in the brain bursts (hemorrhagic stroke).
- Heart failure: Failure occurs as a result of your heart’s inability to increase pressure, or blood flow, into the body, which can cause your heart to grow in size. This condition can lead to failure of other organs throughout the body.
- Peripheral artery disease (PAD): This is when the peripheral arteries, the blood vessels that carry blood from the heart to the rest of the body, become narrow, usually because of cholesterol buildup. High blood pressure can lead to this buildup of plaque in the arteries.
- Aneurysms: Aneurysms occur when an artery bulges out. Some aneurysms go undetected, and some burst, causing bleeding inside the body. Aneurysms can happen in any of the body’s arteries but are most commonly seen in the aorta, brain, legs, and abdomen. High blood pressure can cause weak spots in the vessels to bulge out more easily because of the increased pressure.
- Kidney disease: High blood pressure can cause narrowing in the arteries of the kidney, making it harder for the kidneys to effectively clean your blood and remove excess fluid, placing even more pressure on the blood vessels and further increasing blood pressure.
How does sleep affect blood pressure?
According to the CDC, more than one in three people in the United States are sleep deprived, getting less than the recommended seven hours of sleep a night. Unfortunately, insomnia and blood pressure can go hand-in-hand.
According to Dydyk, when you’re sleep-deprived, your body can make increased amounts of cortisol, known as the stress hormone. Higher levels of cortisol can be a factor in developing high blood pressure and your ability to get restful sleep. The more sleepless nights you have, the more your blood pressure could rise because these hormone changes happen over time. If you have already been diagnosed with hypertension, stress and sleeplessness can raise your blood pressure even more.
Cortisol levels are usually lower at night when you’re sleeping. When levels are elevated, this can increase wakefulness and blood pressure. Dydyk added that even older adults with normal blood pressure can experience an increase in blood pressure at night when they have higher levels of cortisol in their blood.
“Increases in stress hormones such as cortisol can directly increase blood pressure by stimulating our sympathetic nervous system—our fight or flight system,” said Dydyk. And it’s not just sleep that’s affected. According to Dydyk, the fight or flight response can also affect hunger hormones, as well as male and female sex hormones, like estrogen and testosterone.
One way blood pressure can be affected by sleep is through nocturnal (nighttime) dipping (when your blood pressure drops during sleep). Research suggests nocturnal dipping might be connected to our circadian rhythm—the body’s internal clock, which operates on a 24-hour cycle. It essentially tells you when you should sleep and when you should wake up.
Getting good sleep can lower stress hormones, noted Dydyk. “It’s restorative. It regulates our body. And our blood pressure is lower while we sleep, which puts less strain on our blood vessels.”
A blood pressure drop of 10%–20% overnight compared to daytime blood pressure is normal, said Dydyk. But when nocturnal dipping doesn’t take place, such as what happens when you aren’t getting enough sleep, your blood pressure may stay at the daytime high and may even go up, increasing your chances of having a heart attack or other cardiovascular event.
Too much sleep, which some of us do to compensate for our lack of sleep, can also cause concerns. It can raise your risk of other health conditions, like high blood sugar and weight gain—both of which can also place increased pressure on your heart and other organs.
If you’re getting poor sleep, you might want to get evaluated by your health care provider for sleep apnea, especially if you have high blood pressure. If you’re still feeling tired in the morning despite getting enough sleep, or if you snore, it would be a good idea to talk with your provider, since sleep apnea can increase your risk of hypertension, as well as other health problems.
How to get better sleep to improve blood pressure
Getting quality sleep can sometimes be challenging. Here are some ways to improve your sleep quality (and hopefully lower your blood pressure):
Have a consistent sleep schedule
The CDC recommends getting at least seven hours of sleep a night. To get your body into a good sleep-wake cycle, it can help to have a schedule where you go to sleep and wake up at the same time every day.
It might be tempting to lie awake in hopes you’ll eventually fall asleep, but if it’s been 20 minutes and you’re still awake, head out of your room to play some relaxing music, meditate, drink a calming tea, or do some breathing exercises. Reading a book can also help you wind down, but resist the urge to turn on your TV because television is a known disrupter of sleep. Once you feel sleepy, go back to bed. You may have to do this a few times until your body gets the hint.
Set up your ideal sleeping environment
Create an environment that’s inviting, cozy, and ideal for a restful night’s sleep. Some tips:
- Have a comfortable bed. You spend hours a night sleeping. Make sure your mattress is comfortable and supportive. If you’re experiencing pain from an uncomfortable mattress, consider replacing it with mattress that provides upper and lower back support, which may help prevent back pain. If you are looking for recommendations, read our review of the best mattresses for back problems. Also consider an adjustable bed.
- Keep your room cool. It’s usually easier to fall asleep in a cooler room than in a room that’s too warm. If you don’t have an air conditioner, use a fan or crack your window to get a breeze. A cooling mattress may also help.
- Reduce blue light. Looking at your phone, computer screen, or TV before bed can keep you awake.
- Avoid large meals before bed. Eating a large meal before bed can keep you awake and feeling uncomfortable. If you’re having trouble getting to sleep, don’t eat within a few hours of going to bed.
Consider your sleep position
Sleeping on your back can cause your tongue to fall back in your throat, blocking your airway. This can lead to snoring and sleep apnea, which is often linked to high blood pressure.
According to Connor, you should sleep on your left side if you have high blood pressure. “This puts less strain on blood vessels, and in turn, less strain on our heart.” It also helps to keep your airway from being obstructed, which can decrease snoring and help you breathe more deeply through the night.
Of course, you want to sleep in the position most comfortable for you, but Dydyk added that sleeping on the right side can compress the blood vessels bringing blood back to your heart, which can potentially slow the blood circulating through your body, especially for people who already have narrowed arteries.
Stay active during the day
Daily exercise isn’t just good for helping you sleep better at night, it can also help lower your blood pressure. Just make sure you’re not exercising too close to bedtime because this might keep you awake.
Bottom line
Sleep is when your body slows down and decreases the rapid flow of blood through your arteries. It’s important to prioritize sleep because high blood pressure can impact many parts of the body. Talk to your doctor about your sleep concerns so you can work toward a solution.
Have questions about this article? Email us at reviewsteam@ncoa.org.
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