Here are a few excerpts from the Paleolithic Solution that explain a bit about sleep, stress and increased cortisol levels:

…Most people are familiar with the idea that cortisol is a “stress” hormone, but this is misleading and more a function of our modern lives than cortisol really being a “stress” hormone.  Cortisol is in fact critical to life

A normal day for our Paleolithic ancestors would start by awakening with relatively high cortisol levels…This is nature’s way of making sure we are alert, energized, and ready to go!  Cortisol causes the release of glucose and fatty acids from the liver.  That’s energy our Paleolithic ancestors needed to move camp, hunt, gather, and generally get the day going…In the evening, when we are winding down and going to bed, Cortisol should drop

When you are subjected to stress, particularly chronic stress [as opposed to the more normal fight or flight acute stressors we were designed to meet] your body releases cortisol much more frequently than it should.  This gets ugly when cortisol is not only high in the morning, but all day long, even at bedtime…It is a nasty snowball effect…Abnormally elevated cortisol begins to disturb sleep, which makes us more prone to daily stress, which raises cortisol.  The consequences of this downward spiral include suppressed immune function, chronically elevated blood sugar levels, decreased insulin sensitivity, impaired ability to form long-term memory, and decreased sex drive and libido.  Yes folks, cortisol is a big deal

If we are chronically insulin resistant and have elevated blood glucose levels from cortisol, it is quite similar to eating a high-carb diet.  Advanced glycation end-products age our skin and organs at an accelerated rate.  Insulin resistance causes us to store fat around the waistline and we tend to not use body fat for energy.  Additionally, elevated cortisol destabilizes the protein collagen, which is what gives youthful skin its, well, youthfulness!  Even if your food is pretty good, you can undermine your health by mismanagement of stress and sleep

…(explaining a case study for a guy named Charlie) Normally, our cortisol is low at night to allow us to go to sleep.  In Charlie’s case, he is in a stage of burnout in which his cortisol is actually high in the evening and rock bottom in the morning…A common solution to this problem is downers at night and uppers in the AM.  Downers usually entail a few glasses of wine and an ever-increasing dose of coffee in the moring.  The problem is the wine makes that disturbed sleep even worse because it blocks the critical release of growth hormone in early sleep.  The escalating morning stimulant dose helps initially, but it just digs a deeper hole in the long run...

HERE are a few tips for sleeping better.