The relationship between the condition and hypertension  

When the pressure of your blood (especially within your arteries) is abnormally high, it can put a massive strain on your cardiovascular system.  

 High blood pressure is therefore a risk factor for serious health conditions, such as heart disease and stroke.  

 The condition (also called hypertension) can be treated with the right medication and changes to your lifestyle. It is also important you address other health problems that could be contributing to the condition.  

One such health issue could be untreated or poorly treated obstructive sleep apnea (OSA). This is a disorder where a person’s breathing involuntarily stops and starts as they sleep due to obstruction of the upper airway.¹

How OSA can cause hypertension  
Every time you stop breathing during sleep, your sympathetic nervous system gets activated, and consequently your blood pressure spikes. The role of the sympathetic nervous system is to control our fight-or-flight response and help us respond when we are under stress. The system does this by triggering complex reactions within our bodies that include an elevated heart rate, faster metabolism, and, of course, higher blood pressure.⁷   

These reactions are supposed to happen. However, when you have OSA, your stop-start breathing causes them to activate so often that you can end up with chronic hypertension.  Stress hormones that are released during this response are called catecholamines and can also cause hypertension.⁷ 

It is estimated that as many as half of the people diagnosed with OSA have underlying hypertension.^₂  

What happens to your blood pressure if you have OSA?  
When you are sleeping your blood pressure lowers by 10 to 20%. This reduction is perfectly normal and is called blood pressure dipping. When you have severe OSA, your blood pressure fails to dip as much as it should – and this can increase your risk of cardiovascular issues.^3,4   

 Coupled with this, people with OSA can experience a dramatic rise in their blood pressure when they wake up. Known as a morning surge, this blood pressure rise is also a serious risk factor for cardiovascular disease and mortality.⁸   

 Research shows OSA can cause your heart rate to remain elevated throughout the day. Overall, it is thought the more severe your OSA, the higher your blood pressure is likely to be.⁵   

Chat to your healthcare professional   
If you are diagnosed with OSA there are many ways to treat it successfully. In addition to making lifestyle changes, your doctor may ask you to undergo a therapy called continuous positive airway pressure (CPAP).  

 Research shows that CPAP can be particularly effective at treating people who have both OSA. This involves wearing a CPAP mask while you sleep that pushes air into your lungs to keep the airway from narrowing or closing. For many patients, this treatment has resulted in lower blood pressure not only at night but during the day as well. It has been found to reduce stress hormone levels, which further decreases hypertension.⁶    

 Talk with your doctor about any concerns you may have about hypertension or sleep apnea. Getting a regular health check-up can be key to identifying high blood pressure, especially when you don’t have any obvious signs.   

See, What is Obstructive Sleep Apnea? and How is sleep apnea diagnosed?.