High blood pressure is a condition that affects the heart. What does it have to do with your sleep? Research shows that lack of sleep may cause high blood pressure in some people. At first glance, the connection between the two seems unlikely. But if you take a closer look, you’ll see that sleep affects more than just your daily caffeine intake.
Lack of sleep and blood pressure feed off each other. The less sleep you get, the more likely you are to have high blood pressure. Research indicates that high blood pressure, especially at night, increases your risk of heart disease. Because many Americans are sleep deprived, they are also more likely to develop heart problems. Here is how lack of sleep causes high blood pressure and what you can do to reverse it.
What is High Blood Pressure?
High blood pressure, also known as hypertension, is a condition where the blood that flows through your arteries does so at pressures that are greater than normal (1). Blood pressure is the force in which blood presses against your blood vessel walls as it flows through. For most healthy adults, normal blood pressure measures below 120 mmHg with a diastolic pressure of below 80 mmHg (1). A healthcare professional can measure your blood pressure levels by using a stethoscope, an electronic sensor or a gauge along with a cuff that is attached to your upper arm.
When taking your blood pressure, a healthcare worker measures your systolic pressure, which is the pressure of your blood when your heart beats while pumping blood. They also measure diastolic pressure, which is when the heart is resting between beats. If you’re active or exercising, your blood pressure typically increases. But once the activity stops, your blood pressure should return to normal. Blood pressure may naturally rise as you get older. Increased body weight can make your blood pressure go up. For example, newborn babies have very low blood pressure while older teens and adults have the highest.
High blood pressure occurs in adults who have a reading of 120/80 mmHg or greater. The top number is your systolic number, and the bottom is your diastolic number. It reads as “180 over 80” millimeters of mercury. The following is a list of the stages of high blood pressure in adults (1):
- Prehypertension: systolic number of 120-139 or a diastolic number of 80-89
- Stage 1 of high blood pressure: systolic number of 140-159 or a diastolic number of 90-99
- Stage 2 of high blood pressure: systolic number of 160 or higher or a diastolic number of 100 or higher
The two main types of blood pressure are primary and secondary. Primary or essential hypertension is the most commonly diagnosed form of high blood pressure. It develops over several years as a person becomes older. Secondary high blood pressure is a symptom of another medical condition or drug. It is treated by addressing the underlying condition.
Can Lack of Sleep Cause High Blood Pressure?
Studies show that even slight increases in blood pressure, especially nighttime blood pressure, enhances the risk of death from cardiovascular disease (2). Both insomnia and sleep deprivation are linked to high blood pressure. These conditions also increase the risk of restless legs syndrome, which is linked to high blood pressure. Other sleep related conditions that contribute to hypertension are obstructive sleep apnea and continuous positive airway pressure.
Sleep alters the functionality of the autonomic nervous system and other vital body processes that control blood pressure. When you sleep normally, your blood pressure naturally decreases compared to when you’re awake. This drop in blood pressure is known as nocturnal dipping (2). Regular nocturnal dipping is considered to be 10 to 20 percent lower in both systolic and diastolic numbers than when you’re awake. On the other hand, non-dipping occurs when your blood pressure drops less than 10 percent.
People who do not have proper levels of nocturnal dipping are at an increased risk of developing cardiovascular diseases (2). One study noted that people who only have a 5 percent nocturnal dip in blood pressure were 20 percent more likely to die from cardiovascular related problems (2). Conditions that may cause decreased nocturnal dipping are high blood pressure, older age, diabetes, obstructive sleep apnea, and chronic kidney disease (2).
Research shows that your sleep duration may determine your blood pressure levels. Several studies have found that subjects who slept five hours or less each night were at a greater risk of developing high blood pressure (2). One study of 4,810 people between the ages of 32 and 59 who slept for five hours or less had a 60 percent increased risk of developing high blood pressure at their eight to ten year follow up appointments (2). Interestingly, the study found no association in people over 60. Results of the survey show that middle age people who are sleep deprived tend to have a higher risk of developing hypertension later in life.
Another study evaluated sleep duration in subjects over a three day period by using a wrist actigraphy. Researchers calculated the subject’s sleep quality and five-year incidence of hypertension in 578 adults between the ages of 33 and 45. Results showed that for each hour of sleep the subject’s lost, they had a 37 percent increased risk of developing high blood pressure (2). Even children who don’t sleep well are at risk of high blood pressure. A study of 238 adolescents either with or without sleep apnea or other medical conditions who slept less than 6.5 hours a night were 2.54 times more likely to have high blood pressure (2). Additionally, poor sleepers had an increase of 4 mmHG in systolic blood pressure and were 3.5 times more likely to develop prehypertension (2).
Sleeping seven to eight hours is recommended for most healthy adults. Getting more than that is not always better. The Sleep Heart Health Study determined that longer sleep durations also increase the risk of high blood pressure (2). One study found that sleeping for an hour longer than necessary decreased nocturnal dipping and did not elevate blood pressure levels when subjects woke up (as they normally do) (2).
It’s no surprise that people with insomnia are at a greater risk of high blood pressure. One study that followed 8,757 people over six years determined that subjects who had problems falling asleep, staying asleep, and who did not have enough restorative sleep were more likely to develop hypertension (2). Again, older people with insomnia don’t appear to be at an increased risk of high blood pressure. This was confirmed by a study involving 1,419 people aged 73 and above with insomnia. At their six-year follow-up appointment, no signs of hypertension were noted (2).
Insomnia is associated with a higher nighttime systolic blood pressure reading. Insomniacs do not have a dip in their blood pressure levels when they wake up as good sleepers do (2). Daytime diastolic levels were also found to be higher in people with insomnia, which puts them at an increased risk of developing heart problems. One theory is that high blood pressure shortens sleep duration, which increases the risk of high blood pressure. The two conditions are continuously feeding off each other. Research shows that approximately half of all people with insomnia may eventually develop hypertension (2).
How Does High Blood Pressure Affect Your Health?
Studies have confirmed that lack of sleep increases your risk of high blood pressure. But what does that mean for your health? Firstly, it creates a dangerous situation for your heart as well as your brain. The more pressure that is put on your blood vessels, the greater the risk of a rupture. High blood pressure may cause your blood vessels to become narrow or leak. This can cause blood clots that block blood flow to your brain, which may result in a stroke.
High blood pressure may increase your risk of a heart attack. The harder your heart has to work to pump blood throughout the body, the more strain is put on it. Eventually, your heart may become overworked and give out completely. According to researchers at the Mayo Clinic, approximately half of all people who leave their hypertension untreated die of heart disease due to poor blood flow (3). Poor blood flow to your body also means your skin and other important organs are not getting the oxygen and nutrients they need to stay healthy.
High blood pressure may affect your kidneys, which are needed to filter toxins and waste from your blood. Healthy blood vessels are necessary for the kidneys to do their job. High blood pressure in arteries that lead to the kidneys may cause kidney disease, failure, scarring or an aneurysm (3). High blood pressure can also cause problems in your eyes, such as nerve damage, blood vessel damage, or fluid buildup below the retina (3). This may cause bleeding within your eye, vision loss, scarring, or blurry vision.
Tips for Reducing Blood Pressure
Reducing your blood pressure can help you sleep. It also alleviates a significant amount of strain from your heart and reduces your likelihood of other health complications. Before taking a high blood pressure medication, ask your doctor if you can treat your condition naturally. There are many proven remedies for lowering blood pressure that do not involve a prescription drug. Simple changes to your lifestyle can do the trick. Here are a few that work, according to the Mayo Clinic (4):
1. Lose weight.
Need some motivation to drop a few pounds? Weight loss doesn’t just lower your blood pressure. It also helps you sleep. Studies show that blood pressure increases as your weight does. Dropping just ten pounds can have a significant impact on your blood pressure. According to research, carrying too much weight around your waist is especially harmful to your blood pressure. Men with a waist measurement of 40 inches or greater and women with a measurement of 35 inches or more are more likely to develop hypertension (4).
Exercising for 30 minutes, at least five days a week can help lower your blood pressure by up to 9 mmHg (4). Consistency is key as high blood pressure can return if you stop exercising. Researchers at the Mayo Clinic stated that the best exercises for high blood pressure are walking, running, riding a bike, dancing, and swimming. Resistance training should also be incorporated into your training plan.
2. Focus on your diet.
Your food intake is highly influential over your blood pressure levels. Eating processed foods that are high in sodium, fat, and sugar may increase blood pressure. Research shows that reducing sodium can lower your blood pressure by 8 mmHg (4). Aim for less than 2,300 mg of sodium a day. Start by cutting out all fast food from your diet. Don’t add salt to any food that you’ve prepared and stay away from canned foods. You can never go wrong with eating lots of fresh fruits and vegetables. Choose water or herbal tea over soda. It may help you to keep a food diary or work with a nutritionist to determine what your problem areas are.
3. Stop smoking immediately.
Smoking poses a significant threat to your heart. It increases your blood pressure minutes after you finish smoking a cigarette. If you smoke throughout the day, you are always increasing your blood pressure. According to a 2010 study, quitting smoking is the single most effective way to prevent cardiovascular disease, inflammation, and arterial stiffness (5). The study found that smoking raises blood pressure by stimulating the sympathetic nervous system. Data shows that smokers with high blood pressure are more likely to develop accelerated atherosclerosis as well as more serious forms of high blood pressure. Consult a professional if you need help with quitting as stopping cold turkey is not always recommended and may result in a relapse.
4. Improve your sleep.
One of the easiest ways to reduce your blood pressure is to improve your sleep. Start by adjusting your sleep habits. You might need to develop a bedtime routine or drink less caffeine during the day. Most people are too stressed to sleep. Research shows that individuals who meditate have higher levels of melatonin than those who don’t. It may also help to improve the comfort level of your bedroom. Turn off all lights and electronics before bed and sleep in total darkness. It may also help to take a natural sleep aid right before bed.