High Blood Pressure: A Side Effect of Insomnia?
High blood pressure (clinically known as hypertension) affects about 75 million Americans. It has many causes, though many don't realize poor sleep — especially insomnia — is a common cause.1
How might insomnia be linked to high blood pressure?
Blood pressure changes during sleep
The biological process of sleep is more complex than simply lying down and shutting your eyes. It provides time for the body to heal, recuperate and recharge, playing a critical role in overall health.2
Moving from wakefulness to sleep involves a variety of transitions regulated by the circadian system. These transitions include shifts in vital signs such as body temperature, pulse, and breathing pattern.
During some sleep stages, blood pressure typically "dips" between 10 and 20 percent from daytime levels. This "nocturnal dipping" helps you achieve restful sleep. Dipping blood pressure reduces stress on the heart, giving it time to recover from strain taking place during the day.2,3
What about people with insomnia?
However, for people with insomnia, sleep loss may prevent them from experiencing adequate dips.
Insomnia describes the inability to fall asleep or maintain a full night of sleep (sleeping less than 7 hours every night).2
Someone experiencing insomnia often faces a night of arousals: moments when the brain and body awaken, disrupting the sleep cycle and interfering with sleep stages.
Hyperarousals (typical of insomnia) greatly disturb sleep. They contribute to increases in sympathetic nervous system activity which elevate blood pressure during sleep.4-6
Sleep disorders linked to higher blood pressure
Population-based studies continue to show that as many as half of all people with insomnia face a significantly higher risk for developing hypertension.7,8
That’s a lot, considering that 1 in 2 adults experience short-term insomnia at some point in their lives, while another 10 percent experience chronic insomnia.1
Other sleep disorders that contribute to higher nocturnal blood pressure include:8-11
- Sleep apnea
- Shift work disorder
- Restless legs syndrome (RLS)
- Periodic leg movements in sleep (PLMS)
- Short sleep syndrome
- Insufficient sleep (generally linked to lifestyle)
Dippers versus nondippers
Unfortunately, some people are "nondippers" who struggle with the mechanisms that regulate blood pressure. They experience a less than 10 percent drop in blood pressure overnight. Even if they sleep all night.12,13
This puts them at increased risk for hypertension and its risks, especially stroke, heart attack, and kidney problems. Researchers find that nondippers generally experience more arousals in sleep and tend toward more fragmented, disrupted sleep.2,3
In the end, this ultimately leads to increased blood pressure, specifically at a time in the 24-hour cycle when the brain and body need it to dip.4
Other abnormal blood pressure patterns related to the sleep-wake cycle include:13
- Hypertension during the night
- Hypertension early in the morning
Who’s at risk for being a nondipper?
Possible causes include sedentary living, higher sodium intake, smoking, diabetes, chronic renal disease, and abnormal regulation of nervous system hormones.14
The many consequences of maintaining high blood pressure during sleep point to an overloaded cardiovascular system and negative impacts on the heart muscle, veins, arteries, and kidneys.12
Those with hypertension, either unable to control it or fail to treat it, face serious consequences:4
- Damaged arteries
- Coronary artery disease
- An enlarged left heart
- Heart failure
- Kidney damage and failure
- Vision dysfunction
How to help yourself
If you have chronic insomnia and notice an upswing in blood pressure, you'll want to talk to your doctor about ways to address your sleeplessness. Treatments may include cognitive behavioral therapy for insomnia (CBTi), biofeedback to “dampen” arousals, and some medications used to achieve adequate, quality sleep.
If you already have hypertension and you experience chronic insomnia, sleeplessness will likely worsen your blood pressure. Your best bet? Actively treat both problems with the help of a knowledgeable physician.15
Watch your medications
Many kinds of medications cause insomnia. Ironically, alpha-blockers and beta-blockers — used to treat hypertension — may also contribute to sleeplessness. Discuss your medications with your doctor if you suspect this problem.16
Practice good sleep hygiene
Sleep hygiene — those actions you take to make sleep possible — may not eliminate insomnia, but it’s still a worthwhile approach. Doctors generally review sleep hygiene strategies first to see whether these easy, low-cost efforts can provide quick relief. Good sleep hygiene includes:1
- Maintaining a regular sleep-wake schedule
- Exposing yourself to natural light early in the day
- Getting adequate physical activity
- Avoiding blue spectrum light — commonly emitted from handheld electronic devices like smartphones and tablets — at least 1 hour before bedtime
- Going to bed at least 2 hours after eating and drinking
- Avoiding caffeine, high fat foods, high sugar foods, and alcohol at bedtime
- Having a “sleep friendly” bedroom that’s cool, dark, and quiet
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