|"Insomnia" by Gabriel Ward. Courtesy DeviantArt.|
Recent research continues to show measurable correlations between behaviors of insomnia and high blood pressure. But how might insomnia physiologically lead to high blood pressure?
During the process of sleeping, your blood pressure falls to a consistent low until you wake up again. (The exception is during REM sleep, but if you have insomnia, your odds of experiencing REM are very low.)
While at rest, your heart should be working at an easy-to-manage default pace while the remainder of your systems repair, restore, and rejuvenate themselves overnight. Most active processes, like digestion, slow down in order to allow the sleep process to work its healing magic.
Unless, of course, you can't sleep through the night.
Insomnia is defined here as the inability to fall asleep or to stay asleep for the full night, even when given the perfect opportunity to do so. If you have insomnia, this means you are either never fully falling asleep, or you are moving from sleep to wakefulness all night, leading to sleep fragmentation.
Did you know that every arousal sets off a chain reaction of chemical processes in your body? This flood of various hormones into your bloodstream, including stress hormones like cortisol, can disrupt your ability to maintain sleep. Higher cortisol results in lower melatonin and higher adrenaline. You need melatonin to maintain sleep, while adrenaline is all about alertness.
One night of insomnia may have very little long-term impact on your health; the human body is resilient and can recover from brief, temporary episodes of sleeplessness. But if you go through a stretch of weeks or months of insomnia, the constant presence of these stress hormones in your blood during sleep can negatively impact other processes, leading to problems with insulin sensitivity, vascular chemistry, and systemic inflammation. So, not only are you not sleeping, but you are also opening the doorway to potential disease onset.
Add to this the fact that insomnia is frequently caused by the emotional stress in everyday life (not just Big Picture stress like divorce, but day-to-day stress like coping with moody teenagers), and you can see how stress can lead to these same uninvited hormones hijacking your systems even while you are not sleeping.
Research confirms that people with chronic insomnia experience chemical and process imbalances throughout their body not only during the day, but at night as well. These processes include higher frequency brain activation, abnormal hormone levels, higher metabolism, elevated heart rate, and more activity coming from the sympathetic ("fight or flight") nervous system, regardless the time of day.
It's as if the body and brain never get a chance to rest.
What about that eight or so hours of sleep at night that your body needs to repair itself at the cellular level? What about that eight or so hours of sleep at night that the brain needs to synthesize the information and experiences of the day?
Sleep is necessary to give all of your organs the rest they require to function optimally. This includes your heart. These lost hours of sleep are, in essence, holding your organs hostage to stress. Over time, this stress to your system will result in, among other things, higher blood pressure, as the hormones in your bloodstream will gradually alter the default mechanics of your heart. When your heart is fueled regularly by high octane cortisol, day and night, it will not be able to avoid wokring on overdrive even while at rest. This leads to oxidative stress over time and a worn-out ticker.
If you are concerned about long-term insomnia and its potential negative impact on your blood pressure, please consult your physician to identify the root cause of both your insomnia and to identify whether you might have hypertension. Treating insomnia may likely benefit both conditions.
The relationship of sleep duration and insomnia to risk of hypertension incidence: a meta-analysis of prospective cohort studies. Meng L, Zheng Y, Hui R. Hypertension Research (2013) 36, 985–995; DOI:10.1038/hr.2013.70; published online 5 September 2013.
Insomnia linked to hypertension. Henry Ford Health System via ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2012/06/120606142706.htm
Do Insomnia Complaints Cause Hypertension or Cardiovascular Disease? Phillips B, Mannino DM. Journal of Clinical Sleep Medicine. Aug 15, 2007; 3(5): 489–494.