When it comes to sleep, knowing how much to get can be confusing. Too little isn’t good, but too much can also cause problems. One health factor, in particular, that can feel the repercussions of both these extremes is blood pressure—it can increase whether you sleep too much or too little.
With our blood pressure requiring that our nightly sleep fall within a specific range, how can we determine how much sleep is best?
We’ve combed through the research connecting sleep and hypertension to better understand how your sleep habits can affect your risk of hypertension (it’s not just how long you sleep, either!) and what sleep habits we can adopt to keep our blood pressure from rising too high.
How Does Sleep Affect Blood Pressure?
Research has continually shown that sleep is closely related to the development of hypertension. As for why this occurs, it is likely because sleep duration, especially if you sleep too little, can increase the activity of your sympathetic nervous system (“fight-or-flight”) and reduce the activity of your parasympathetic nervous system (“rest and digest”).
When your body is continually in fight-or-flight mode, your heart rate will speed up, and there will be a decrease in heart rate variability (HRV), which is the time between each heartbeat. Generally, a higher HRV is preferred because it means you have good cardiac fitness and spend more time in “rest and digest.”
As for why HRV is important, a low HRV is associated with a greater risk of hypertension. This means that too little sleep, which increases your sympathetic nervous system and lowers HRV, can increase the risk of hypertension.
Too much sleep can also contribute to hypertension, though. Sleeping for too long can increase the presence of certain inflammatory factors, which circulate through the body, causing inflammation. In addition to making you feel drowsy and fatigued (even though you slept for a long time), these inflammatory markers can also increase the risk of hypertension.
Sleeping for a long time can also increase blood pressure because long sleep duration has been associated with sleep fragments, which activate the sympathetic nervous system and raise blood pressure.
If the research concerning blood pressure and sleep duration makes anything clear, it’s that too much and too little sleep can cause a problem, so you need to find the optimal middle ground.
How Long Should I Sleep To Prevent Hypertension?
If you’re at risk of hypertension, optimizing your sleep to prevent any additional risk is crucial for preserving your health.
Research has shown that, when compared to those who sleep for 7 to 8 hours a night, those who sleep for less than 6 hours have a 36% to 66% increased risk of hypertension. Furthermore, sleeping for more than 9 hours comes with an 11% to 30% increased hypertension risk. Of note, these risk increases are based on average sleep times—not getting enough sleep one night will not immediately increase your hypertension risk.
Based on these statistics, it’s recommended to aim for 7 to 9 hours of sleep each night to maintain a healthy blood pressure.
It’s Not Just Sleep Duration
While sleep duration is important for controlling your blood pressure, it’s not the only element of your sleep that is a key player; light exposure, as well, can influence your sleep and blood pressure.
Research has shown that having a sleep-wake cycle inconsistent with the external environment (i.e., being a night shift worker who sleeps during the day and works at night) can increase arterial pressure by 3%.
Additionally, being exposed to light at night, such as through indoor lighting or electronic screens, can decrease your production of melatonin (the sleepiness hormone), making sleep harder to come by and increasing your blood pressure.
Along with light exposure, having an irregular sleep schedule, even if you hit the 7-9 hour recommendation each night, can also increase your risk of hypertension. A study even found that something as simple as sleeping in on the weekend—which you may spend all week looking forward to—can cause enough variation in your sleep schedule to substantially increase your risk of high blood pressure.
As for how much sleep variations may affect you, the study found that waking up only 43 minutes later can increase your hypertension risk by 9%. Even more, those having sleep schedule variations of 2+ hours each night were 85% more likely to have hypertension than those who only had an hour’s difference in sleep timing each night. This makes it clear that the more irregular your sleep schedule, the more your blood pressure can suffer.
In general, anything that disrupts your circadian rhythm, whether it be nighttime light exposure, catching up on sleep, or switching time zones, can dysregulate your blood pressure variability, leading to an increase in nighttime blood pressure.
Sleep Habits That Promote Good Blood Pressure
With blood pressure being nicknamed “the silent killer” because of its ability to cause years-long damage without your knowledge, any steps you can take to reduce your risk of hypertension and keep your blood pressure within a normal range can significantly improve your health.
When it comes to sleep habits, these are some options to implement to help reduce your risk of hypertension:
- Get enough sleep, but not too much. There’s a sweet spot when it comes to sleep duration and your hypertension risk; too little or too much, and you can increase your risk. For your health, aim for 7–9 hours of sleep each night.
- Lower the lights at night. Once the sun goes down and you approach bedtime, try dimming the lights and reducing your use of electronic devices. This will make it easier to fall asleep and helps lower the risk of hypertension from short sleep duration.
- Avoid weekend sleep-ins. As tempting as it may be to sleep in on the weekend, these sleep schedule variations may increase your blood pressure. Instead, try to reconfigure your sleep schedule so you can get more sleep every night (lessening your need to catch up on sleep debt.)
- If you do sleep in, keep it short. If you desperately need to sleep in or have to stay up later than normal, remember that the smaller the variation, the better.
- Get checked for a sleep disorder. If you struggle to get enough sleep, it may be because of a sleep disorder. Certain disorders, such as obstructive sleep apnea, can also increase your risk of hypertension, so if you suspect a sleep disorder, it’s best to talk to your doctor about it.
Sleep influences numerous aspects of your health and well-being, and blood pressure is just one of them. To understand more about how sleep affects your health and the good sleep habits to implement to reduce disease risk factors, such as hypertension, check out Pillow’s resource library.
