Updated on August 24, 2023.
You probably know from experience that getting enough sleep is important for your health. Missing crucial rest at night can leave you feeling foggy, fatigued, and lacking the energy you need to get through your day.
Chronic lack of sleep is also linked to a number of health conditions, including diabetes, depression, and dementia. Research has also found that lack of sleep, too much sleep, and poor sleep quality can dramatically increase your risk of cardiovascular disease and stroke.
How too little or too much sleep may affect the heart
Health experts recommend that the optimal amount of sleep for adults is seven to nine hours per night. Getting about that amount of good sleep each night may help reduce your risk of heart disease and stroke, according to a 2022 article in the European Heart Journal.
The study looked at the lifestyle habits of more than 7,000 people and scored their sleep from zero (lack of sleep) to five (a good night’s worth). The researchers found that people in the study who had the best sleep scores enjoyed a 74 percent reduction in their risk of heart disease compared to those who had the lowest scores, and for every point a person’s score rose, their chances of stroke and heart disease dropped 22 percent. According to the data, if all participants in the study had scores of five, nearly 71 percent of new cases of cardiovascular disease and stroke could be prevented annually.
A 2021 study in the American Journal of Preventive Cardiology monitored 17,635 people over seven years and found that sleeping less than six hours increased the risk of death related to cardiovascular disease.
Quality counts, too
The amount of sleep you get is clearly important, but the quality is as well. People who sleep fewer than six hours and those with fragmented or restless sleep have a higher risk of atherosclerosis (thickening or hardening of the arteries) than people who sleep a solid seven to eight hours, according to a 2019 study in the Journal of the American College of Cardiology.
But sleepyheads beware. Among women in the 2019 study, sleeping longer than eight hours increased the risk of atherosclerosis. And the 2021 study found that sleeping more than seven hours also increased the risk of death from cardiovascular disease.
In 2018, researchers in the U.K. analyzed 74 studies of more than three million people. Their findings, published in the Journal of the American Heart Association, found that the longer people slept over seven hours, the greater their risk of heart complications and death. People who slept 10 hours had a 30 percent greater risk of death than people who slept seven hours. Those who slept 11 hours had an increased risk of 47 percent.
Questions about cause and effect
When you’re sleeping, your body uses the downtime to recover from the strains of the day. And a host of things happen during the night that impact whether your heart gets the chance to recuperate.
First, your blood pressure lowers while you are sleeping by 10 to 15 percent. This dip is an important rest for your heart, particularly if you have high blood pressure, one of the leading causes of both heart attack and stroke.
In the American Journal of Preventive Cardiology study, researchers found that people who slept too much or too little had high levels of CRP, a protein that indicates when inflammation is present in the body. Inflammation is known to increase the risk of both heart attack and stroke because it can lead to increased plaque and hardening of the arteries.
Your body also regulates hormones at night, including ones that suppress appetite and keep you from overeating. If these hormones get out of whack owing to poor or insufficient sleep, it may make you more likely to seek out fatty or sweet snacks, which may increase your risk of obesity—another risk factor of cardiovascular disease.
The connection between sleeping too much and heart disease is not understood as well as sleep deprivation. But researchers think it could be that conditions like chronic inflammatory disease, diabetes, or depression—which may make a person sleep more than usual—also contribute to cardiovascular disease. If you are sleeping too much, you may also not be getting enough physical activity, which can lead to obesity.
Improve your sleep, boost your heart
Whether your sleep deprivation is a result of long hours at work, a stressful home life, or a medical condition that contributes to insomnia, you’re not alone. According to the Centers for Disease Control and Prevention, more than a third of American adults don’t regularly get at least seven hours of sleep.
If you have sleep apnea or another condition that is impacting your amount or quality of sleep, talk to your healthcare provider (HCP) about treatment options. If a heart condition that causes pain or anxiety is keeping you awake, relaxation techniques like yoga, deep breathing, or meditation may help.
If you just have a difficult time getting to bed at night or notice you are a restless sleeper, try some of these tips to get more shut-eye:
- Avoid alcohol, caffeine, and fatty foods for at least an hour before bedtime.
- Wake up and go to bed around the same time each day, even on weekends.
- Avoid your phone, laptop, and TV at least an hour before bed.
- Keep your bedroom dark, quiet, and at a comfortable, cool temperature.
- Get plenty of exercise during the day. (But working out close to bedtime can keep you awake.)
Some risks for heart disease and stroke—like genetics and age—are out of your control. But it’s important to remember there are lifestyle factors that you can change, like diet, exercise, and sleep, to improve your heart health.
