What causes insomnia?

There are two types of insomnia – primary and secondary. Primary insomnia refers to sleeplessness that cannot be attributed to an existing medial, psychiatric or environmental cause (AASM). If your insomnia stems from an underlying condition – such as other sleep or mental disorders, or substance abuse – it’s called secondary insomnia. 

Here’s a comprehensive list of biological, psychological and social factors that may contribute to insomnia: 

• Stress and anxiety. If you’ve experienced a traumatic event, such as losing your job, the death of a loved one, or divorce, it’s very natural for your body to feel more stressed. Unfortunately, racing thoughts and worry are basically the antitheses of sleep because they can keep your mind active at night. 
   
• Depression and other mood disorders. There is a very strong association between sleep disturbance and major depression. A chemical imbalance in the brain may be to blame for disrupting sleep patterns. Fears and troubling thoughts may also play a contributing factor. In one survey, researchers that 97% of people reported sleep difficulties during depression episodes, and 59% of these indicated that poor sleep significantly affected their quality of life — further exacerbating a vicious cycle between insomnia and essentially all mood disorders.  Depression, bipolar disorder, anxiety, and post-traumatic stress disorder have all been shown to cause sleep problems. 
   
• Age. Biological changes can make sleep more difficult as we age. Sleep disturbance is common in people with dementia, musculoskeletal disorders, and bladder instability. Elderly people also tend to take more medications that may disrupt sleep. 
   
• Prescription drugs and over-the counter medications. Some cause insomnia, while others disrupt sleep quality (e.g. frequent trips to the bathroom) or trigger daytime drowsiness.  These include:  

• • • • Antidepressants 
      • Antihistamines 
      • Decongestants or other allergy medications 
      • Heart and blood pressure medicines 

• Stimulants. These are substances that affect the central nervous system and body, resulting in increased alertness and difficulty in getting to sleep. Many of your favorite beverages (e.g. coffee, tea, soft drinks and energy drinks) contain coffee, for example, which stimulates the brain. This particular substance takes up to six hours for the body to digest, so if you consume too late into the day, then you might have a harder time falling asleep later at night.  
   
• Alcohol. This is a sedative that may help you fall asleep initially, but it will prevent you from reaching the deeper stages of sleep that are necessary to carry out important biological functions while you sleep – such as forming memories, removing toxins, and keeping the tissues and organs throughout your body healthy. If you’re unable to relax into these deeper stages of sleep, it’s very likely that you’ll find yourself tossing and turning throughout the night. 
   
• Medical conditions. Many primary medical conditions can contribute to insomnia, such as: chronic pain, breathing difficulties, sleep apnea, arthritis, diabetes, cardiovascular disease, cancer, overactive thyroid, menopause, and obesity. If you suffer from any of these conditions and are experiencing insomnia, consult with your doctor on how you can address the primary concern and improve your sleep patterns. 
   
• Sleep disorders. It’s very possible to experience insomnia if you have been diagnosed with other sleep disorders. For example, restless leg syndrome causes an uncontrollable urge to move your legs. Sleep apnea, which affects more than 936 million people worldwide, makes it difficult to control your breathing at night – often resulting in snoring, gasping for air, and frequently waking up. 
   
• Environmental changes. The human body is biologically programmed to operate within a 24-hour cycle that is mostly dependent on light exposure. So, naturally, you should wake up when the sun rises and go to sleep when it’s dark outside. However, many people do shift work, which forces them to differentiate their sleep/wake cycle from the normal rhythm that regulates the body’s sleep cycles, body temperature, and metabolism. Similarly, traveling across time zones can result in jet lag symptoms, including insomnia.