Several studies have shown a link between hypertension and an abnormal breathing pattern during sleep called obstructive sleep apnea (OSA). Hypertension is common in patients with OSA. There is also evidence that OSA can lead to the development of hypertension.
People with OSA have repeated interruptions in breathing during sleep. This is caused by collapse of the main breathing passage in the back of the throat. Every time this passage is blocked, breathing stops and oxygen is used up. After some time (usually 10-20 seconds, although up to one minute is not unusual) the breathing difficulty causes a brief awakening.
The awakenings are often so short that the person is unaware of any interruption in sleep. The awakening relieves the blockage in the breathing passage and normal breathing resumes. Unfortunately, when the person falls back asleep, the entire process can repeat (often hundreds of times per night). The drop in oxygen level from not breathing, and the increase in heart rate and blood pressure caused by waking up, causes stress for the heart. These nightly increases in blood pressure eventually lead to permanent increases in blood pressure, even during the day.
It is important to treat hypertension. Hypertension is a known risk factor for the development of other forms of cardiovascular disease such as heart attack, heart failure, and stroke. But treating hypertension may not be enough if the key reason for a person’s high blood pressure is an unrecognized sleep disorder like OSA.
Hypertension medications, for instance, may not work well in a patient with untreated OSA. Many people who have difficult cases of hypertension are later found to have untreated OSA. Treatment of OSA can improve hypertension. For this reason, it is important for your healthcare professional to investigate all of the possible causes of your hypertension, including sleep disorders like OSA.
