Sleep Apnea and High Blood Pressure

Yes, sleep apnea can raise your blood pressure. Each time your airway closes during sleep, your oxygen drops and your body releases stress hormones that tighten blood vessels and push blood pressure up. Treating sleep apnea can lower blood pressure a little, and it matters most for people whose blood pressure stays high even on several medicines.

How sleep apnea raises blood pressure

In obstructive sleep apnea, the throat relaxes and closes off the airway again and again during sleep. Each pause sets off a chain reaction:

• Oxygen drops — Air stops moving, so the oxygen level in your blood falls.
• Stress hormones surge — Your brain senses the problem and switches on the body's "fight or flight" system to wake you just enough to breathe.
• Blood vessels tighten — These hormones narrow blood vessels and speed up the heart, so blood pressure jumps.
• It repeats all night — In severe sleep apnea, this happens 30 or more times an hour.^[1]

Over months and years, this stress system can stay switched on during the day too. That can leave blood pressure high around the clock, not just at night. Low oxygen may also strain and inflame blood vessel walls.

When blood pressure does not dip at night

In healthy sleep, blood pressure normally drops at night. Doctors call this "dipping." It gives your heart and blood vessels a rest.

Sleep apnea is closely tied to high blood pressure at night and to a "non-dipping" pattern, where blood pressure stays high while you sleep. You cannot see this on a reading taken in the office. A 24-hour blood pressure monitor, worn at home overnight, can show it. Your doctor may order one if your daytime readings do not tell the whole story.

Sleep apnea and resistant hypertension

Resistant hypertension means blood pressure stays above goal even though a person takes three blood pressure medicines of different types, usually including a water pill (diuretic). It also includes people who need four or more medicines to reach goal.^[2]

Sleep apnea is very common in this group. In some studies, most people with resistant hypertension had sleep apnea.^[3] For this reason, the American Heart Association recommends screening for sleep apnea in people with resistant or poorly controlled high blood pressure.^[4] American heart and blood pressure guidelines also list sleep apnea as one of the causes of high blood pressure to look for when numbers will not come down.

Sleep apnea and heart disease are linked in other ways, too. Our article on how sleep apnea affects heart health covers atrial fibrillation, heart failure and stroke, and our guide to sleep apnea and heart disease explains the risks of leaving it untreated.

What CPAP does for blood pressure

CPAP keeps your airway open with gentle air pressure, so the oxygen drops and hormone surges stop. Research on blood pressure shows a real but modest benefit:

• In people with high blood pressure — Studies that pool many trials found CPAP lowered 24-hour blood pressure by about 2 points (mmHg) on average.^[5]
• In resistant hypertension — Pooled trials found a larger drop, about 5 points in the top number over 24 hours.^[3] Nighttime readings often improved the most.^[3][5]
• Using it matters — The benefit seems larger in people who use CPAP most of the night, every night.^[5] A machine in the closet does not help.

A few points may sound small, but over time even small drops in blood pressure may help lower heart and stroke risk. CPAP also treats the snoring, tiredness and poor sleep that come with sleep apnea. If CPAP is hard to use, our CPAP tips can help.

Keep taking your blood pressure medicines

CPAP is not a replacement for blood pressure medicine. On average, it lowers blood pressure only a few points.^[3][5] Most people with sleep apnea and high blood pressure still need their medicines.

• Do not stop or cut back on your own — Stopping some medicines suddenly can make blood pressure jump.
• Keep your primary care doctor or cardiologist in the loop — They manage your blood pressure and may adjust your medicines as your readings change.
• Healthy habits still help — For people with overweight, weight loss together with CPAP can lower blood pressure more than CPAP alone.

Morning headaches and home blood pressure checks

Some signs at home can point to sleep apnea. Morning headaches, loud snoring, gasping or choking at night, and feeling tired after a full night in bed are common clues. Our list of signs you might have sleep apnea has more.

If your doctor asks you to check your blood pressure at home, write down the time of each reading. Include some morning readings. Bring your log to your visits with your primary care doctor and your sleep doctor. A pattern of high readings, even on medicine, is a good reason to ask about a sleep test.

When to get tested for sleep apnea

Ask your doctor about a sleep apnea test if you have high blood pressure and any of these:

• Blood pressure that stays high — Even on three or more medicines, or it is hard to control.^[2]
• Loud snoring or breathing pauses — Especially if a bed partner has seen you stop breathing or gasp.
• Daytime sleepiness — Dozing off while reading, watching TV or driving.
• Morning headaches — Or waking up unrefreshed most days.
• Heart rhythm problems — Such as atrial fibrillation.

Many adults can start with a home sleep apnea test. Others need an in-lab sleep study, depending on their health. A sleep specialist can help you choose, read the results and plan treatment, while your primary care doctor or cardiologist keeps managing your blood pressure.

Sleep apnea care at Teddy Bear Pediatrics & Sleep Medicine

Dr. Minal Patel is board-certified in Pediatrics and Sleep Medicine and sees adults and children for sleep problems. The practice offers in-lab and home sleep tests, CPAP and BiPAP therapy, and Inspire evaluation. Medicaid and CHIP are accepted for sleep medicine patients. The office is open Monday to Friday, 8:30 AM to 5:00 PM, and is accepting new patients by appointment (no walk-ins).