A common cause of a rising heart rate during sleep is a lack of oxygen, which is often brought on by obstructive sleep apnea. This is a condition where a person’s normal breathing frequency is reduced or sometimes flat-out stopped during sleep. The effort to breathe persists, but with the upper airway blocked, oxygen levels drop and carbon dioxide levels rise.
These blockages involve the softening of the muscles around the throat, soft palate, uvula, and tongue base. When the occurrence of these interruptions—referred to as apneas—are in excess (more than five times per hour of sleep), a formal diagnosis of sleep apnea from a doctor may follow.
When breathing ceases during sleep, the brain recognizes that things aren’t right, and wakes the sleeping person up, kickstarting normal breathing functions once again. Not only is a person’s sleep quality compromised because of sleep apnea, they also cause the heart to beat faster than usual.
Heart rate and oxygen levels
Let’s walk through what happens when your breathing stops and your brain is cut off from a sufficient oxygen supply while you sleep.
When an apnea occurs, regular respiratory function ceases. As a result, the heart kicks into high gear, thinking that the reason your body isn’t getting its proper oxygen supply is because it simply isn’t pumping blood fast enough. This is similar to what happens during strenuous exercise, and why the heart beats faster to distribute oxygen throughout your body.
But this time, you’re not exercising—you’re asleep, and you’re not breathing. The heart wants to compensate for this deficit in oxygen and pumps faster and faster, but the blood moving through your circulation is de-oxygenated and isn’t helping you out very much. At around this time, your brain’s panic mode is triggered, and it rouses you out of your sleep. This is accompanied by a burst of cortisol (stress hormone). Your pulse is spiking, you wake up and gasp for breath, and in doing so, take a big gulp of air.
Finally, your body gets the oxygen it needs, and your pulse goes down again. But the damage from this disruptive episode has already been done. Namely, your sleep has been disrupted, even if you don’t remember waking up, and your pulse has been much higher than it needs to be.
Sleep apneas can happen dozens, sometimes hundreds, of times each night. Spikes in your heart rate at that frequency isn’t healthy in the long term—these repeated episodes stress the health of your heart.
Oxygen and CO2 balance
When we breathe in, we inhale oxygen to the lungs all the way down to the alveoli. These are little air sacs where oxygen is then transferred into the blood stream via hemoglobin on the red blood cells. Oxygen is then transported via our arteries to all the organs and tissues in the body. Once it arrives at those tissues, the oxygen is released for us to use. Hemoglobin exchanges oxygen for the carbon dioxide byproduct of using the oxygen from the last trip and brings it back to the lungs for you to exhale. This is how it works when everything is functioning as it should.
As life would have it, sometimes things get turned upside down, or knocked off kilter. One very common example is the remarkably prevalent habit of breathing too much. Yes, too much. That might be breathing too fast (rate), taking in too much air (volume), or a combination of the two. When we over breathe, we blow off too much CO2, and this causes other problems.
Breathing is unhealthy and strongly correlated with many issues, like bone facial structure, sleep apnea and more.
It also causes you to expel too much carbon dioxide from your body, which can cause fluctuations in your blood’s pH level and limit the hemoglobin from releasing oxygen into our cells. This is called the Bohr effect, which can ultimately lead to hypoxia or low blood oxygen levels that restrict blood flow to vital organs. Breathing through your mouth will make it more likely that you hyperventilate and lose oxygen!
This means that even while exercising it is better to breathe through your nose than your mouth. While it can be tempting to exhale through our mouths to cope with heavy exertion, this does us fewer favors than maintaining a proper balance of oxygen and carbon dioxide.
Additionally, breathing through the nose allows us access to a small portion of nitric oxide that we carry into our lungs. Nitric oxide helps with maintaining the balance of our bodies. It also helps to dilate our lungs and blood vessels, while providing antibacterial properties to clear out germs and bacteria.
- Avoid breathing from the mouth at all costs.
- Nasal breathing increases nitric oxide production in the sinuses, which has been linked to reduced inflammation, improved sleep, improved memory, and an overall increase in immune system function.
What can you do
Breathe less : From a holistic stand-point of view what you can do to make sure your carbon dioxide is in a good range is to breathe less! Most of us are “over breathing,” which means we inhale too much air and decrease the amount of carbon dioxide in our system. This changes our pH and can make us feel the symptoms of dysfunctional breathing.
The trick is to breathe in and out less, slower, low in the body, AND in a way that feels comfortable for your body. Don’t worry, it takes some practice and plenty of patience. This will also help you to grow your lung capacity.
Block your mouth with a tape : During your sleep you should always breath through the nose. The process behind mouth taping works exactly as it sounds: You literally tape your mouth shut before you go to sleep.
- Try to establish to always breathe through the nose to improve your sleep and your overall health.