How Does Sleep Affect Heart Health and Blood Pressure?

When you fall asleep and enter non-REM sleep, your blood pressure and heart rate fall, and your heart does not work as hard as it does when you are awake, according to NHLBI: Why Is Sleep Important?. That page says people who do not sleep enough or wake up often during the night may have a higher risk of coronary heart disease, high blood pressure, obesity and stroke. A second page words it this way: over time, not getting enough quality sleep, called sleep deficiency, can raise your risk of heart disease, obesity, high blood pressure, diabetes, and stroke (NHLBI: Get Enough Good-Quality Sleep).

Sleep helps heal and repair your heart and blood vessels, in that second page’s words. It lists 7-9 as the recommended hours of sleep a day for adults 18 years or older, in a table of American Academy of Sleep Medicine recommendations.

What happens to blood pressure and heart rate while you sleep?

The “Why Is Sleep Important?” page describes two systems. During sleep, your parasympathetic system controls your body. During REM sleep and when waking, your sympathetic system is activated, increasing your heart rate and blood pressure to the usual levels when you are awake and relaxed. The page adds that a sharp increase in blood pressure and heart rate upon waking has been linked to angina, or chest pain, and heart attacks.

In stage 3 non-REM sleep, the period of deep sleep, your heartbeat and breathing slow to their lowest levels during sleep, according to NINDS: Brain Basics: Understanding Sleep. On the same page, REM sleep first occurs about 90 minutes after falling asleep, and in REM sleep your heart rate and blood pressure increase to near waking levels.

MedlinePlus: Healthy Sleep lists “Give your heart and blood vessels a rest” among the things certain phases of sleep help you do. It adds: “You need all the stages to get a healthy sleep.”

This site keeps a copy of Your Guide to Healthy Sleep, a patient and public booklet updated in 2011 and reproduced as archived reference, not current guidance. According to the booklet, the changes throughout the night in blood pressure and heart and breathing rates seem to promote cardiovascular health. It adds that if you don’t get enough sleep, the nightly dip in blood pressure that appears to be important for good cardiovascular health may not occur.

Which health problems are linked to too little or poor-quality sleep?

Four of the pages cited above print a list of conditions. The first table gives each list in the page’s own words. The second table takes each condition and tallies which of the four lists name it.

People who are chronically sleep deprived are more likely to be overweight, have strokes and cardiovascular disease, infections, and certain types of cancer than those who get enough sleep, according to the NINDS page. It describes a key focus of research as understanding the risks involved with being chronically sleep deprived and the relationship between sleep and disease.

From the MedlinePlus page: “It's not just the number of hours of sleep you get that matters. The quality of the sleep you get is also important.” People whose sleep is frequently interrupted might not get enough of certain stages of sleep, it adds.

Studies have shown that not getting enough quality sleep can lead to a decreased ability to respond to insulin, the “Why Is Sleep Important?” page reports. Its list goes on to increased consumption of food, especially fatty, sweet, and salty foods, decreased physical activity, and metabolic syndrome. The list ends: “All of these contribute to overweight and obesity.”

In the archived Your Guide to Healthy Sleep booklet, a lack of sleep puts your body under stress and may trigger the release of more adrenaline, cortisol, and other stress hormones during the day. The booklet continues: “These hormones keep your blood pressure from dipping during sleep, which increases your risk for heart disease.”

How does sleep apnea affect the heart?

NHLBI: Sleep Apnea Symptoms lists three symptoms of sleep apnea that you may have while asleep: breathing that starts and stops, frequent loud snoring, and gasping for air. NHLBI: Living With Sleep Apnea reports that sleep apnea can cause low oxygen levels during sleep and prevent you from getting enough quality sleep. It adds that it takes a lot of effort to restart breathing many times during sleep, and this can damage your organs and blood vessels.

These factors may raise your risk for heart and blood vessel diseases, the “Living With Sleep Apnea” page continues. It gives seven examples: atrial fibrillation, atherosclerosis, difficult-to-control high blood pressure, heart attack, heart failure, pulmonary hypertension, and stroke. Type 2 diabetes and metabolic syndrome are on the same list of conditions.

A document on this site dated September 1995 discusses the consequences of sleep apnea and how to identify patients at risk, and it is reproduced as archived reference, not current guidance. The document states that the cardiovascular system is also adversely affected by sleep apnea. Its next sentence reports that systemic hypertension has been reported in up to 50 percent of patients with sleep apnea.

A project page on this site, Sleep Apnea Education in Latino Communities, states its objective as developing an educational tool on obstructive sleep apnea for the lay Latino public. The page also states: “Hypertension and obesity are strongly associated with sleep apnea.”

Which sleep signs should you raise with a provider?

“Talk to your healthcare provider about your symptoms,” the “Sleep Apnea Symptoms” page advises. The five checks below are yes-or-no questions taken from that page, the MedlinePlus page and the NINDS page, with the source named in each.

1. Has someone noticed it while you sleep? Breathing that starts and stops, frequent loud snoring, and gasping for air are the symptoms the “Sleep Apnea Symptoms” page lists for while you are asleep, and it adds: “You may not know you have these symptoms until someone tells you.”
2. Are you sleepy and tired in the daytime? The same page lists daytime sleepiness and tiredness, which can lead to problems with learning, focusing, and reacting.
3. Do you wake up often during the night to urinate, or have a dry mouth or a headache? All three are on that page’s list of symptoms you may notice yourself.
4. Do you have trouble getting up in the morning, have trouble focusing during the day, or doze off during the day? MedlinePlus poses these three questions and follows them with: “If you answered yes to any of these questions, you may need to improve your sleep habits.”
5. Do you have problems sleeping, or feel unusually tired during the day? The NINDS page’s advice is to see a doctor in either case, and it adds that most sleep disorders can be treated effectively.

A patient booklet on this site identifies the signs of problem sleepiness, and its list includes falling asleep while driving and struggling to stay awake when inactive, such as when watching television or reading. The booklet, reproduced as archived reference, describes sleep apnea as a serious disorder in which a person’s breathing is interrupted during sleep. Its advice: “If you think you are getting enough sleep, but still feel sleepy during the day, check with your doctor.”

This guide is general education. What a symptom means for you is a question for your own health care provider.

When are heart attack or stroke signs an emergency?

NHLBI: Heart Attack Symptoms gives this instruction: “Any time you think you might be having a heart attack, don’t ignore it. Call 9-1-1 for emergency medical care, even if you are not sure that you’re having a heart attack.” Acting fast can limit damage to your heart and save your life, the page states. It also tells readers not to drive to the hospital or let someone else drive them.

Chest pain, heaviness, or discomfort in the center or left side of the chest is the most common symptom, according to that page. Its list also has pain or discomfort in one or both arms, your back, shoulders, neck, jaw, or above your belly button, and shortness of breath when resting or doing a little bit of physical activity. Light-headedness or sudden dizziness and a rapid or irregular heartbeat are on the list too.

For stroke, MedlinePlus: Stroke gives this instruction: “If you think that you or someone else is having a stroke, call 911 right away.” The symptoms it lists are sudden numbness or weakness of the face, arm, or leg (especially on one side of the body); sudden confusion, trouble speaking, or understanding speech; sudden trouble seeing in one or both eyes; sudden difficulty walking, dizziness, loss of balance or coordination; and sudden severe headache with no known cause.

The same page gives the F.A.S.T. test: face drooping on one side when smiling, arm weakness when the arms are raised, speech that is slurred or strange, and time to call 911. It adds: “Every minute counts during a stroke.” More pages on sleep are listed on the sleep topic page.