man who can't sleep staring at clock What is the most common sleep complaint?  If you guessed insomnia, then you are correct.  Insomnia is the most common sleep complaint in the general population, with a prevalence of approximately 10%. It is described by difficulty falling and staying asleep, accompanied by some kind of daytime fatigue and/or impairment.

The disturbance may consist of one or more of three features: (1) difficulty in initiating sleep; (2) difficulty in maintaining sleep; or (3) waking up too early. A fourth characteristic, nonrestorative or poor-quality sleep, has frequently been included in the definition.

  1. Do you have Difficulty Falling Asleep? (DFA)
  2. Do you have Sleep Continuity Disturbances? (SCD)
  3. Do you wake up feeling exhausted and Non-Restored? (NRS)

*A combination of 3 sleep complaints (DFA, SCD, NRS) predicted a slightly increased risk of cardiovascular disease but not hypertension, and a complaint of either DFA or SCD predicted increased hypertensive risk

There are 2 types of insomnia – primary and secondary insomnia (secondary being the most common type).  If you have secondary insomnia, it means that your insomnia is a side effect of an underlying problem (or multiple problems).  These could include things like OSA or other sleep disorders, TMD pain and related symptoms, anxiety, depression, medications, substances like caffeine or alcohol, restless leg syndrome, etc. Other common comorbidities would include things like ADHD and substance abuse.

Because insomnia sufferers cannot achieve good quality sleep, their blood pressure and nervous system levels remain abnormally higher than someone without insomnia. Insomnia can elevate the resting heart rate, which leads to hypertension and cardiovascular disease (CVD).  Congestive heart failure insomnia is prevalent in these cases. Alternatively, patients with CVD are more likely to suffer from insomnia. This can be due to rapid eye movement during sleep, sleep-disordered breathing, angina pain, OSA, or paroxysmal nocturnal dyspnea (PND).
Many patients with insomnia can be predisposed to CVD, especially people who sleep less than 6 hours per night. Other predictors include being of the female sex, older age and/or psychiatric conditions. It has been proven that more women than men die of CVD, and it is the leading cause of death throughout the Western World.

By the year 2020, it is estimated that nearly 40% of all deaths worldwide will be due to CVD (more than twice the percentage of deaths from cancer).

Spiegelhalder K, Scholtes C, Riemann D. (2010). The Association Between Insomnia and Cardiovascular Diseases. Nature and Science of Sleep. 2: 71–78.

Phillips B, Mannino DM. Do Insomnia Complaints Cause Hypertension or Cardiovascular Disease? J Clin Sleep Med 2007. 35: 489–494.

Willerson JT, Ridker PM. Inflammation as a Cardiovascular Risk Factor. Circulation. 2004 Jun 1;109 (21 Suppl 1):II2-10.

ASA (American Sleep Association) website

Phillips B1, Mannino DM. Does Insomnia Kill? Sleep. 2005 Aug 1;28 (8):965-71.

Sleep Review Magazine

Insomnia Patients Have Higher Risk of Dying from Cardiovascular Disease

January 25, 2017