Sleep disorders such as obstructive sleep apnea (OSA), insomnia, co-morbid insomnia and obstructive sleep apnea (COMISA), restless legs syndrome (RLS), circadian rhythm disorders, narcolepsy, and sleep fragmentation can significantly increase the risk of heart disease.
The consequences of inadequate sleep is not just feeling exhausted the next day.
Lying awake when you should be sleeping, stopping breathing dozens of times during the night, or feeling that irresistible urge to move your legs just as you are about to fall asleep, puts you heart under strain.
They are established cardiovascular risk factors that increase the likelihood of high blood pressure, heart attack, stroke, heart failure, and abnormal heart rhythms.
The importance of healthy sleep is now reflected in modern heart health guidelines.
The American Heart Association includes sleep as one of its Life's Essential 8 measures of cardiovascular health, alongside blood pressure, cholesterol, blood sugar, diet, physical activity, body weight, and avoiding tobacco.
That shows that the quality of your sleep is closely linked to the health of your heart.
This article explains which sleep disorders are most strongly linked to heart disease, how they damage the cardiovascular system, the warning signs that a sleep disorder may already be affecting your heart, and the practical steps you can take to reduce your risk.
When sleep is repeatedly disturbed, whether by frequent awakenings, breathing interruptions, or simply getting too little sleep, blood pressure often fails to fall as it should during the night. Stress hormones such as cortisol remain high, the body's fight-or-flight response stays switched on, and inflammation persists instead of settling down.
These can predispose you to heart diseases.
During healthy sleep, your cardiovascular system enters its recovery period.
Blood pressure falls naturally, a normal process known as nocturnal dipping.
Heart rate slows, stress hormone levels decline, inflammation decreases, and blood vessels have an opportunity to recover from the constant workload of the day.
This nightly recovery helps keep arteries flexible, supports healthy blood pressure, and reduces wear and tear on the heart.
Sleep disorders interrupt that recovery.
Over months and years, those changes begin to damage the cardiovascular system.
Blood vessels become stiffer, the inner lining of the arteries functions less effectively (endothelial dysfunction), blood pressure gradually rises, and the conditions that promote plaque buildup become more established.
The longer poor sleep continues, the greater the strain placed on the heart.
That is why treating a sleep disorder is about far more than getting a good night's rest. In many cases, it is also an important step toward protecting your heart.
Read More: How Does Poor Sleep Affect The Heart?
Obstructive sleep apnea (OSA) is one of the most common sleep disorders that increase your heart disease risk.
It happens when the muscles in your throat relax during sleep, causing the airway to become blocked repeatedly.
Breathing stops for a few seconds before the brain briefly wakes the body to reopen the airway. Most people never remember these awakenings, but they can happen hundreds of times in a single night.
Each episode causes blood oxygen levels to fall while blood pressure and heart rate suddenly rise as the body activates its fight-or-flight response.
Over time, these repeated stress events damage blood vessels, promote inflammation, impair endothelial function, and increase oxidative stress, all of which increase heart disease risk.
People with untreated OSA are significantly more likely to develop high blood pressure, coronary artery disease, atrial fibrillation, heart failure, stroke, and premature cardiovascular death.
The risk increases as sleep apnea becomes more severe.
Loud snoring, choking or gasping during sleep, waking with headaches or a dry mouth, excessive daytime sleepiness, and feeling un-refreshed despite a full night's sleep are common warning signs.
Insomnia is more than the occasional sleepless night.
It is persistent difficulty falling asleep, staying asleep, or getting restorative sleep despite having enough opportunity to sleep, usually occurring at least three nights a week for three months or longer.
Although many people think of insomnia as mainly a quality-of-life problem, research shows it is also an independent risk factor for cardiovascular disease.
If you have chronic insomnia, you have a higher rate of developing hypertension, coronary heart disease, heart failure, recurrent heart attacks, and cardiovascular death than those who sleep well.
Much of this damage happens because insomnia keeps the body in a prolonged state of stress.
Cortisol and sympathetic nervous system activity remain high when they should normally fall during sleep, leading to higher blood pressure, reduced heart rate variability, increased inflammation, and loss of the normal nighttime drop in blood pressure that allows the heart to recover.
If insomnia becomes chronic, it should not be dismissed as simply "poor sleep." Addressing it early may improve both sleep quality and long-term cardiovascular health.
Some people have both chronic insomnia and obstructive sleep apnea at the same time. This condition is known as COMISA (co-morbid insomnia and sleep apnea).
Research suggests it carries an even greater cardiovascular risk than either disorder alone.
Around 20-40% of people with sleep apnea also have insomnia, while about 30-40% of people with insomnia have underlying sleep apnea.
A study found that their is higher long-term risks of cerebrovascular disease, ischemic heart disease, inflammatory heart disease, arrhythmias, and thrombotic disorders in people with COMISA.
The reason is simple. Sleep apnea repeatedly interrupts breathing, while insomnia prevents the restorative sleep needed for the heart to recover between those breathing interruptions.
Together, they expose the cardiovascular system to almost continuous overnight stress, increasing inflammation, sympathetic nervous system activity, and blood vessel damage.
If you have sleep apnea but still struggle to sleep, or you have chronic insomnia and also snore loudly or wake up gasping for air, it is worth discussing both conditions with your doctor. Treating both together offers better cardiovascular protection than treating either one alone.
Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a neurological disorder that causes an overwhelming urge to move the legs, usually during the evening or at night.
Many people describe the sensation as crawling, tingling, aching, or burning deep inside the legs, with temporary relief only after moving them.
Although RLS is usually discussed as a sleep problem, it also has important cardiovascular implications.
Every periodic leg movement is accompanied by a temporary rise in heart rate and blood pressure.
When this happens repeatedly throughout the night, the normal nighttime drop in blood pressure becomes less effective, sympathetic nervous system activity remains elevated, and the heart misses part of the recovery that healthy sleep normally provides.
Over time, these repeated cardiovascular stress responses may contribute to hypertension, endothelial dysfunction, inflammation, and an increased risk of cardiovascular disease.
Several studies have also found that people with frequent or severe RLS symptoms are more likely to have coronary artery disease and other forms of cardiovascular disease than those without the condition.
Circadian rhythm disorders include delayed sleep phase syndrome, shift work disorder, irregular sleep-wake rhythm, jet lag disorder, and even chronic sleep schedules that change dramatically between weekdays and weekends.
Your body follows a 24-hour internal clock known as the circadian rhythm. This biological clock controls much more than your sleep.
It also regulates blood pressure, heart rate, hormone release, metabolism, and inflammation. When your sleep schedule regularly falls out of sync with this internal clock, your cardiovascular system also becomes disrupted.
A study involving more than 300,000 adults found that people who naturally stayed up late had poorer heart health and higher cardiovascular risk than early sleepers, even when they slept for similar numbers of hours.
Likewise, shift workers like healthcare workers, security personnel, factory workers, and hospitality staff people with irregular sleep schedules have higher rates of hypertension, coronary heart disease, metabolic disorders, and major cardiovascular events.
The reason is that circadian disruption prevents the normal nighttime fall in blood pressure, alters cortisol rhythms, increases inflammation, and disrupts autonomic nervous system regulation. Over months and years, these small changes increase the likelihood of developing cardiovascular disease.
Narcolepsy is a chronic neurological disorder that affects the brain's ability to regulate sleep and wakefulness.
People with narcolepsy often experience overwhelming daytime sleepiness, sudden episodes of muscle weakness known as cataplexy, sleep paralysis, and vivid dream-like hallucinations when falling asleep or waking up.
Although narcolepsy is relatively uncommon, it has cardiovascular implications.
It may cause irregular heartbeat, increase the risk of heart disease, can lead to sudden muscle weakness and also linked to a higher risk of obesity.
Sleep fragmentation refers to repeatedly waking up throughout the night, even if you eventually fall back asleep each time.
Fragmented sleep prevents the long, uninterrupted periods of deep sleep that the heart depends on for recovery.
Deep sleep is when blood pressure naturally falls, inflammation decreases, cortisol reaches its lowest level, and the cardiovascular system repairs itself after the demands of the day.
When sleep is repeatedly interrupted, these restorative processes are shortened or lost altogether.
If you regularly wake several times every night, even if you think you sleep long enough overall, it is worth mentioning this to your doctor. Sometimes the problem is not the number of hours you sleep, but the quality and continuity of that sleep.
Sleep disorders and depression frequently occur together, and when they do, their effects on the heart appear to reinforce each other rather than simply add together.
Both conditions increase inflammation, disrupt cortisol regulation, and keep the sympathetic nervous system more active than it should be. Together, they reduce the heart's opportunity to recover during sleep.
If you have persistent sleep problems alongside symptoms of depression, addressing both conditions is important, not only for your mental wellbeing but also for protecting your cardiovascular health. Improving sleep quality is often an important part of reducing overall heart disease risk.
Read More: How Does Depression Affect Your Heart?
During healthy sleep, blood pressure naturally falls giving the heart and blood vessels time to recover.
Sleep disorders disrupt this "nocturnal blood pressure dip," meaning the cardiovascular system remains under pressure throughout the night. Over time, this increases the risk of hypertension, stroke, and heart disease.
Instead of slowing down during sleep, the sympathetic nervous system, the body's fight-or-flight system remains overactive. This causes the heart to beat faster, blood vessels to stay constricted, and stress hormones such as adrenaline and cortisol to remain elevated, placing extra strain on the cardiovascular system night after night.
Poor-quality sleep increases inflammatory chemicals that damage the lining of blood vessels. This inflammation encourages fatty plaques to develop and become unstable, increasing the likelihood of heart attacks and strokes.
Many sleep disorders, especially obstructive sleep apnea, cause oxidative stress and endothelial dysfunction. The endothelium, the inner lining of blood vessels loses its ability to regulate blood flow properly, making arteries stiffer and more prone to atherosclerosis.
Healthy hearts constantly adjust their rhythm to meet the body's needs. Sleep disorders reduce heart rate variability, a marker of impaired autonomic nervous system function that has been linked to a higher risk of cardiovascular disease and premature death.
Sleep disorders, particularly obstructive sleep apnea, increase platelet activity and make the blood more likely to clot. Combined with inflammation and damaged blood vessels, this raises the risk of heart attacks and strokes.
The combined effects of inflammation, oxidative stress, high blood pressure, and endothelial damage speed up the buildup of plaque inside the arteries. This narrowing of the arteries is the underlying cause of most heart attacks and many strokes.
Yes. Treating a sleep disorder is not just about improving sleep quality, it can also improve cardiovascular health. The exact benefits depend on the type of sleep disorder.
Some treatment methods for sleep disorders include:
This is the standard treatment for moderate to severe obstructive sleep apnea. By keeping the airway open throughout the night, CPAP reduces repeated drops in oxygen levels, lowers nighttime blood pressure, improves blood vessel function, reduces inflammation, and decreases the frequency of abnormal heart rhythms such as atrial fibrillation. These cardiovascular benefits are greatest in people who use CPAP consistently.
CBT-I addresses the habits and thought patterns that keep insomnia going. Research shows that it improves sleep quality while also reducing cortisol levels, lowering blood pressure, improving heart rate variability, and decreasing sympathetic nervous system activity.
This addresses co-morbid obstructive sleep apnea and insomnia
Both for the breathing interruptions and the chronic sleeplessness, offering better sleep and potentially greater cardiovascular protection than treating either condition alone.
Treatment may include medications that reduce leg movements, and lifestyle changes. By reducing the repeated blood pressure and heart rate spikes caused by periodic limb movements, treatment allows the cardiovascular system to recover more effectively during sleep.
For people with irregular sleep schedules or shift work disorder, maintaining consistent sleep and wake times, getting adequate daylight exposure, and improving sleep hygiene can help restore the body's internal clock. This supports the normal overnight fall in blood pressure, healthier hormone rhythms, and better cardiovascular recovery.
Don't assume persistent snoring, chronic insomnia, restless legs, or excessive daytime sleepiness are "just how you sleep." Identifying the underlying problem is the first step toward reducing its impact on your cardiovascular health.
If you have obstructive sleep apnea and your doctor prescribes CPAP therapy, using it every night is essential. Consistent CPAP use has been shown to lower blood pressure, improve heart rate variability, reduce inflammation, and decrease the risk of heart rhythm problems, especially in people with moderate to severe sleep apnea.
For chronic insomnia, CBT-I is recommended as the first-line treatment because it addresses the underlying causes of insomnia rather than simply helping you fall asleep temporarily.
Studies show it improves sleep quality while also reducing blood pressure, lowering stress hormones, and improving cardiovascular function.
Going to bed and waking up at roughly the same time every day helps stabilize your circadian rhythm. Consistent sleep timing supports healthy blood pressure regulation and may reduce cardiovascular risk, even if your total sleep duration stays the same.
Regular exercise improves sleep quality, can reduce the severity of sleep apnea in some people, eases symptoms of restless legs syndrome, and directly protects your heart by improving blood pressure, cholesterol levels, and overall cardiovascular fitness.
Ongoing stress can worsen both insomnia and heart disease by keeping cortisol and the sympathetic nervous system activated. Simple habits such as relaxation exercises, mindfulness, deep breathing, and maintaining social connections can help improve both sleep and cardiovascular health.
Read More: 9 Ways to Manage Stress Daily that Support the Heart
If you have a sleep disorder, keep track of your blood pressure, cholesterol, blood sugar, and weight. Sleep disorders often contribute to these risk factors long before obvious heart symptoms appear.
Whether you see a primary care doctor or a cardiologist, mention any persistent sleep problems. Sleep should be discussed alongside blood pressure, cholesterol, and diabetes because it plays a direct role in cardiovascular health.
You should see a doctor if you have:
Both insomnia and symptoms of sleep apnea, as this combination (COMISA) carries an even greater cardiovascular risk than either condition alone.
Every night of healthy sleep allows your blood pressure to fall, stress hormones to settle, inflammation to decrease, and your blood vessels to recover. When sleep is repeatedly interrupted whether by sleep apnea, insomnia, restless legs syndrome, circadian rhythm disorders, or a combination of these conditions, that recovery never fully happens. Over months and years, the damage builds quietly until it shows up as high blood pressure, irregular heart rhythms, heart failure, stroke, or coronary artery disease.
Recognizing the symptoms early, getting the right diagnosis, and following treatment can improve both your sleep and your cardiovascular health.
Read More: How Many Hours of Sleep is Good for Your Heart?
Q. Which sleep disorder poses the greatest risk to the heart?
Obstructive sleep apnea has the strongest evidence linking it to hypertension, stroke, atrial fibrillation, heart failure, and coronary artery disease.
Q. Can sleep apnea cause a heart attack?
Sleep apnea doesn't directly trigger a heart attack, but it increases the likelihood by causing repeated drops in oxygen, blood pressure spikes, inflammation, and damage to blood vessels.
Q. Is insomnia really bad for the heart?
Yes. Chronic insomnia is now recognized as an independent cardiovascular risk factor. It increases the likelihood of hypertension, coronary heart disease, heart failure, and heart attacks
Q. What is COMISA?
COMISA stands for comorbid insomnia and obstructive sleep apnea. Having both conditions at the same time places significantly more strain on the cardiovascular system than having either disorder alone.
Q. Can restless legs syndrome affect heart health?
Yes. Repeated leg movements during sleep cause frequent increases in heart rate and blood pressure that interrupt the normal overnight recovery of the cardiovascular system.
Q. Does working night shifts increase heart disease risk?
Yes. Shift work disrupts your circadian rhythm, making it harder for blood pressure, cortisol, and other body systems to follow their normal daily pattern.
Q. Can someone have a sleep disorder without knowing it?
Absolutely. Many people with sleep apnea, restless legs syndrome, or circadian rhythm disorders don't realize they have a medical condition because symptoms develop gradually or occur mainly during sleep.
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