It’s easy to write off snoring as nothing more than a nightly nuisance that drives your partner crazy. However, when you’re dealing with obstructive sleep apnea, there are serious health issues to be concerned about.

Sleep apnea is linked with high blood pressure, a common risk factor for heart disease. Here’s what you need to know about high blood pressure—including recent research on how CPAP lowers blood pressure.

Symptoms and Risks of High Blood Pressure

If you’re thinking to yourself, “I feel fine, there’s no way I have high blood pressure,” that’s your first mistake. According to the American Heart Association, “high blood pressure is a largely symptomless killer.” The reality is that you might not even know you have it.

If untreated, high blood pressure can cause potentially fatal damage to the heart, arteries, brain and kidneys.

How CPAP Lowers Blood Pressure

Obstructive sleep apnea is among the several risk factors for high blood pressure. Sleep apnea patients experience frequent gaps in breathing, which can lead to an increase in blood pressure as the body struggles to maintain a steady oxygen flow.

It makes sense, then, that treating sleep apnea would also help lower blood pressure—and research backs this up. According to a Swiss study published in 2015, CPAP therapy reduced systolic blood pressure by 2.5 mm Hg and diastolic blood pressure by 2.0 mm Hg, which are modest but noticeable amounts. (For those curious, systolic blood pressure is the top number in a blood pressure reading, and diastolic blood pressure is the bottom number.)

Beyond CPAP therapy, the lifestyle changes recommended for sleep apnea patients can also help lower blood pressure. Maintaining a healthy weight, avoiding alcohol and quitting smoking are all considered effective ways to improve both health conditions.

Remember that high blood pressure is a silent killer, so if you suspect you have sleep apnea, talk to your doctor about both related health conditions. The sooner you begin CPAP therapy, the better.