From Doni Wilson (http://doctordoni.com/2014/10/12-causes-of-insomnia.html), here are twelve reasons why you might be having trouble falling asleep (or staying asleep) at night. Others will follow in the coming days.
REASON 1: Timing
Human beings need between 7.5 and 9 hours uninterrupted sleep every night. This means that even if you get 7.5 hours of sleep, but you wake up during the night, you are not getting enough. And it is not just about the number of hours sleep you get. It is also about WHEN you sleep. In one study, nurses who worked the night shift were at increased risk of gaining weight than those who slept between 10 pm and 8 am. Shift work that disrupts your normal pattern of sleep can also increase your cancer risk.
REASON 2: Environment
Everything from light exposure, noise, temperature, electronic devices, television viewing5, allergens, and pets can potentially affect your sleep. In some cases it’s that the environment keeps you awake later and results in you feeling more tired the next day6. In other cases it may be that you are wakened by a pet, child, or noise (snoring bed partner for example), and then find it difficult to get back to sleep. Perhaps you can think of ways the environment in your bedroom may be affecting your sleep.
REASON 3: Waking to use the bathroom
Known as nocturia, night time waking to urinate can also be a cause of disrupted sleep. Whether due to pregnancy, benign prostatic hypertrophy (BPH), interstitial cystitis (inflammation in the bladder), muscle weakness, or another cause which may be related to the other reasons discussed in this article, waking up to use the bathroom can lead to sleep issues as it reduces your hours of uninterrupted sleep (see Reason 1).
REASON 4: Blood sugar imbalances
If your blood sugar spikes and then drops again while you are sleeping, it will quite likely wake you up. This can happen when you eat a high carbohydrate snack before bed (even if it’s fruit). If you have insulin resistance or diabetes, you are more likely to be woken by disruptions in your breathing and decreased oxygen getting to your blood7.
REASON 5: Elevated cortisol
Cortisol should be at its lowest at 10 pm in the evening and remain low until it rises in the morning (peaking at 6 am). With exposure to stress, cortisol levels can be thrown off track and remain high at night. When that happens, sleep is disrupted and insulin becomes less effective8, leading to higher blood sugar levels and weight gain.
REASON 6: Weight gain
Sleep apnea, which occurs when breathing is blocked during sleep causing oxygen levels to drop, is much more likely with weight gain. Both sleep apnea and weight gain increase inflammation and risk of high blood pressure and heart disease9.
REASON 7: Inflammation and pain
Obesity leads to inflammation10 and oxidative stress within the body, both of which are associated with worsening sleep. Inflammation spreads throughout the body and may be felt as pain in your joints, back or nerves (such as with sciatica). This pain can be sufficient to wake you in the middle of the night.
REASON 8: Gluten and other food sensitivities
Sleep issues are common in patients with celiac disease11 as well as those with non-celiac gluten sensitivity, even if they are following a gluten-free diet. I find that many patients with multiple food sensitivities and with leaky gut tend not to sleep well, and that when they eliminate foods based on an IgG and IgA food panel, they report improved sleep. It may seem hard to believe that the gut and brain are so interconnected, but research is now proving the link referred to as the “gut-brain axis12.”
REASON 9: Imbalanced Neurotransmitters
Neurotransmitters, the messengers in the nervous system that determine mood, such as serotonin, dopamine, GABA, and glutamate, can affect sleep when their levels are out of balance. For example, if levels of serotonin or GABA (which are calming neurotransmitters) are too low, then sleep may be interrupted. If dopamine, glutamate, and/or adrenaline (which are all stimulating) are too high, again, it will be difficult to sleep soundly. And it is also well established that neurotransmitters can be thrown out of balance by inflammation and hormone changes.
REASON 10: Hormonal changes, such as peri-menopause
When ovarian function shifts, the hormones produced by the ovaries (estrogen and progesterone) change or decrease, such as with pregnancy, peri-menopause, and post-menopause13. We require the right balance between estrogen and progesterone and if this balance is lost sleep can be affected. In addition, night sweats associated with hormone changes can also cause night time wakings.
REASON 11: Low Melatonin
Melatonin is a hormone that increases at night (its levels are highest at 10 pm), creating our sleep-wake cycle, or circadian rhythm. It has also been associated with the restoration and repair that occurs in our bodies while we sleep. When melatonin levels are decreased, sleep can be disrupted14, either by not being able to fall to sleep, or by not feeling rested in the morning. This is the same effect that occurs temporarily, with jet lag.
REASON 12: Stress
When we are stressed by work demands or other stressful situations, sleep problems can result15. This is true for both adults and children16, and has been shown to lead to elevated cortisol (see Reason 5) and weight gain, which further disrupts sleep (see Reason 6).