Both Too Much and Too Little Sleep Increase Heart Disease Risk

People who carry a genetic predisposition for heart disease can protect themselves by getting the right amount of sleep. Both insufficient and excessive sleep have been linked to a higher chance of heart attack.

Health professionals have long emphasized the benefits of a solid night’s rest. About eight hours of sleep each night typically improves concentration, productivity, immune function, athletic performance, and mood.

Nevertheless, roughly one‑third of U.S. adults do not achieve the recommended sleep duration.

Recent studies show that sleeping too little—or too much—elevates heart‑attack risk, even in otherwise healthy individuals.

Research published in 2019 demonstrated that anyone, including those with a genetic risk for heart disease, can lower their heart‑attack odds by sleeping roughly six to nine hours per night. The authors called this the strongest evidence to date that sleep duration is a key factor for cardiovascular health.

“If someone is looking to optimize their lifestyle, our data suggest that we should also strongly consider whether they are sleeping enough, or too long, as our findings support that these are key lifestyle risk factors contributing to heart health. And this is true in everybody, independent of their risk profile,” said senior author Céline Vetter, assistant professor of integrative physiology at the University of Colorado Boulder.

A 2018 cohort of more than 60,000 adults found that participants who slept fewer than six hours per night faced a significantly higher risk of developing coronary heart disease. Poor sleep quality—such as frequent awakenings or difficulty falling asleep—was also associated with greater risk.

In the same study, individuals who slept more than eight hours showed a modest risk increase, though the result was not statistically significant.

Conversely, a massive meta‑analysis involving over five million people revealed that long sleep duration was significantly linked to higher rates of coronary heart disease, overall cardiovascular disease, stroke, and mortality. The findings suggest that risk rises as sleep extends beyond the typical range.

Together, these investigations highlight that both the quantity and quality of sleep matter for heart health.

While the exact mechanisms remain under study, sleep is known to influence metabolism, inflammation, stress hormones, immune function, and the health of blood‑vessel linings—all pathways that can affect heart disease risk.

“Not sleeping enough can result in metabolic abnormalities (e.g., obesity), inflammation, stress, changes in immune function, and abnormal function of the lining of blood vessels. These can further increase the risk of having a heart attack in those already genetically predisposed to heart disease,” explained Dr. Meir Kryger, sleep expert and pulmonologist at Yale Medicine.

This information is especially valuable for individuals with a family history of heart disease, as prioritizing sleep can markedly reduce their risk.

Sleep difficulties are common. Anxiety, insomnia, age‑related changes, or a newborn’s schedule can all disrupt rest. Chronic sleep disturbance can aggravate existing health problems, particularly cardiovascular ones.

“The heart is a motor that pumps 24 hours a day, 7 days a week, and requires down time, just like a car engine would burn out if it ran nonstop,” noted Dr. Guy Mintz, director of cardiovascular health and lipidology at Northwell Health’s North Shore University Hospital.

Sleep needs vary: some people thrive on seven hours, others on nine. Those who consistently struggle to fall or stay asleep should consult a sleep specialist, who can diagnose underlying causes and recommend treatments such as cognitive‑behavioral therapy for insomnia.

Lifestyle factors also play a role. Timing of exercise, caffeine, meals, and alcohol can all affect sleep quality.

Many experts advise keeping a sleep journal to track bedtime, wake time, and any disturbances. The record can reveal patterns that interfere with the target of 7–9 hours of restorative sleep each night.

In short, whether or not you carry a genetic heart‑disease risk, prioritizing consistent, high‑quality sleep is a simple yet powerful way to protect your cardiovascular system.

“Proper rest is important at any age and life milestone,” Mintz added.

Overall, maintaining a regular sleep schedule of roughly seven to eight hours per night—combined with good sleep quality—remains an often‑overlooked pillar of heart‑health prevention.