Sleep apnea and high blood pressure: what's the link?

Obstructive sleep apnea and high blood pressure are closely linked. Repeated breathing pauses drop oxygen levels and set off a stress response that pushes blood pressure up, and over time sleep apnea appears to raise the risk of high blood pressure. If your blood pressure is high or hard to control and you snore or stop breathing in your sleep, ask your doctor about a sleep test.

How often do the two conditions overlap?

Sleep apnea and high blood pressure overlap often. The American Academy of Sleep Medicine (AASM) says between 30 and 40% of adults with high blood pressure also have sleep apnea. A 2021 American Heart Association (AHA) scientific statement reports that sleep apnea prevalence is as high as 40 to 80% in people with high blood pressure, heart failure, coronary artery disease, atrial fibrillation and stroke.

The same statement says sleep apnea is often underrecognized and undertreated in heart care, even though it is so common in these patients.

The overlap isn't universal. Cleveland Clinic points out that you can have one condition without the other. Of the two main types of sleep apnea, obstructive and central, it says the obstructive type is the one more commonly tied to unmanaged high blood pressure, and it's also the most common type overall. That's the type this article is about.

Does sleep apnea actually cause high blood pressure?

Sleep apnea appears to help cause high blood pressure, and the strongest evidence comes from following people over time. In the Wisconsin Sleep Cohort Study, published in the New England Journal of Medicine in 2000, researchers measured breathing during sleep in 709 adults and checked their blood pressure again four years later. The more breathing events people had at the start, the more likely they were to have high blood pressure at follow-up.

Compared with people who had no events, those with an apnea-hypopnea index (AHI) of 15 or more an hour had nearly three times the odds of high blood pressure four years later. The link held after adjusting for body mass index, neck and waist size, age, sex, alcohol and smoking. The authors concluded that sleep-disordered breathing is likely a risk factor for high blood pressure in the general population.

Observational studies like this one can't prove cause on their own, which is why the evidence rating here is moderate rather than strong. But the pattern fits with what happens in the body during each pause.

How does sleep apnea raise blood pressure?

Sleep apnea raises blood pressure by blocking the dip that normally happens during sleep. Normally, sleep is when blood pressure dips. A Cleveland Clinic sleep specialist explains that heart rate slows, stress hormones fall and blood pressure drops, which gives the heart and blood vessels a chance to rest. Obstructive sleep apnea has the opposite effect.

When the airway collapses and breathing stops, oxygen levels fall. That triggers the body's fight-or-flight response and a surge of stress hormones, which tells blood vessels to tighten and raises blood pressure. With sleep apnea this can happen many times a night, and Cleveland Clinic says those repeated stress responses can strain the heart and blood vessels over time.

Can high blood pressure make sleep apnea worse?

Yes, high blood pressure can make sleep apnea worse, because the link works in both directions. Cleveland Clinic calls the relationship a two-way street. Poorly controlled blood pressure can lead to fluid buildup in the body, and when you lie down at night that fluid can move toward the neck and narrow the airway.

People whose blood pressure doesn't respond well to medicine, known as resistant hypertension, may have even more fluid buildup. Cleveland Clinic says this is partly because resistant hypertension can involve high levels of a hormone called aldosterone, which makes the body hold on to sodium and water.

Who should be checked for sleep apnea?

The AHA statement recommends screening for sleep apnea in people with resistant or poorly controlled high blood pressure. It also recommends screening in pulmonary hypertension and in recurrent atrial fibrillation after cardioversion or ablation.

Other warning signs make a test more worthwhile. The AASM lists snoring with choking, gasping or silent pauses in breathing, daytime sleepiness and obesity alongside high blood pressure. Our guide to snoring vs. sleep apnea explains the signs, and women may have quieter symptoms such as insomnia and night waking, which we cover in sleep apnea in women.

Diagnosis needs a sleep test, either in a sleep lab or, for suitable adults, at home. Our article on the home sleep apnea test explains what to expect.

Does treating sleep apnea lower blood pressure?

Treating sleep apnea does help lower blood pressure, though usually by a modest amount. The AASM's 2019 guideline on positive airway pressure suggests clinicians use PAP to treat sleep apnea in adults with high blood pressure. It rated this a conditional recommendation, meaning the benefit is likely but less certain for every patient.

A 2026 umbrella review of 38 systematic reviews and meta-analyses found CPAP was consistently linked with lower blood pressure, by about 4.8 mmHg systolic and 3.0 mmHg diastolic on average, with improvements in 24-hour readings too. The authors rated the certainty of the evidence as low to moderate. They also said current evidence isn't enough to show that CPAP consistently reduces major cardiovascular events or deaths from cardiovascular causes.

Using it consistently matters. The Cleveland Clinic specialist says CPAP can reduce systolic blood pressure when it's worn through the night. Sleep Education goes further, saying that just one night without treatment can have a negative impact on blood pressure. The NHS lists a lower risk of problems linked to sleep apnea, such as high blood pressure, among the benefits of CPAP.

What other treatments might help both?

The AHA statement says all patients with sleep apnea should be considered for treatment, including behavior changes and weight loss where needed. It says CPAP should be offered to people with severe sleep apnea, and oral appliances can be considered for mild to moderate sleep apnea or for people who can't tolerate CPAP.

Cleveland Clinic says reaching a healthy weight can improve blood pressure and lessen sleep apnea in people with obesity, and that consistently wearing a custom oral appliance may lower systolic blood pressure. Our guides to sleep apnea treatment options and weight loss and snoring go into more detail.

Treating sleep apnea doesn't replace blood pressure treatment. Keep taking any prescribed medicine and don't change it without talking to your doctor.

Do mouth tape or nasal strips help?

No, mouth tape and nasal strips don't help. They are not treatments for sleep apnea and have no role in managing blood pressure. If you have high blood pressure and signs of sleep apnea, see your doctor rather than trying to quiet snoring at home. Our safety page explains when mouth tape isn't appropriate.

This article is general information, not medical advice. Talk to your doctor or a sleep specialist about your own health.

Read next

• Sleep apnea treatments explained
• What is a home sleep apnea test?
• Sleep apnea in women: symptoms that get missed

* This content is for informational and educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure or prevent any disease or health condition. Talk to a qualified healthcare provider about your health.