Causes of Insomnia and Other Sleep Disorders

To improve sleep it is important to identify the causes of insomnia and other sleep disorders. There are a range of causes and these are detailed below, along with some of the consequences of poor sleep.

According to the international classification of sleep disorders, sleep disturbances and in particular insomnia can lead to a range of symptoms including:

• Fatigue or malaise
• Attention, concentration, or memory impairment
• Social or vocational dysfunction or poor school performance
• Mood disturbances or irritability
• Daytime sleepiness
• Motivation, energy, or reduction in initiative
• Increased proneness for errors/accidents at work or while driving
• Tension, headaches, or gastrointestinal symptoms

The table below lists some of the physical, mental, and behavioural conditions associated with extended sleep disturbances. For many, such conditions may be one of causes of insomnia (or sleep disorder), however, studies also show that the reverse is true (i.e., sleep disorders may be a significant cause of these conditions). For example, one study showed that insomnia preceded depression in 69% of cases. Studies have also shown that difficulty falling asleep increases the risk of coronary heart disease by 1.5 to 3.9 times. As you would expect, improvement in sleep patterns is likely to result in positive changes in these conditions.

Causes of Insomnia and Other Sleep Disorders

Studies show that there are a large range of factors that can influence sleep. To effectively treat sleep disorders, these must be assessed and treated. Many of the causes of insomnia are listed below.

• Poor sleep hygiene- one of the major causes of insomnia is poor sleep hygeine. This includes sleeping during the day, engaging in stimulating activities at night, overexposure to light in the evening and eating excessively at night are just some behaviours that are detrimental to sleep.

• Poor diet- stimulants such as caffeine, sugar, and spicy foods are major contributors to sleep disorders. Caffeine can remain in the body for 12 to 20 hours, therefore impairing sleep even if consumed early in the day. Sugar and refined carbohydrate creates sugar imbalances which can also disrupt sleep.

• Alcohol and other drug use- although drinking alcohol may induce sleep, it often creates shortened, lighter sleep. Alcohol is also a strong diuretic, leading to increased nocturnal urination and awakenings during the night. Nicotine stimulates the release of adrenaline and noradrenaline, hormones that stimulate the body, increase heart rate, and elevate blood pressure.

• Disrupted circadian rhythms- the body goes through a sleep-wake rhythm where important hormones and neurotransmitter levels vary throughout the day and night. When these rhythms are disrupted it can lead to sleep disorders. The body clock can be disrupted by inadequate or excess exposure to full-spectrum light and sunlight, shift work, travelling across time zones, poor diet, heavy use of stimulants, lack of exercise, excessive stress, excessive exposure to magnetic and electromagnetic fields, medication use and ill-health.

• Excess physical and emotional stress- excess physical and mental stress will lead to increased levels of stress hormones adrenaline and cortisol and is one of the major causes of insomnia and other sleep disorders. Dysregulation in these hormones can lead to a range of sleep disorders and create a vicious cycle of less sleep and more stress.

• Mental health problems- depression, generalised-anxiety, panic disorder, and post-traumatic stress are just some of the mental health problems that can lead to sleep disorders.

• Medications & supplements- the regular use of prescription and over-the-counter medications and supplements such as heart medications, pain relievers, anti-anxiety drugs, and even sleeping pills has been shown to interfere with sleep, and for some people may be one of the major causes of insomnia and sleep probelms.

• Vitamin, mineral and other nutrient imbalances- Nutrients in the form of vitamins, minerals, essential fats, and amino acids are crucial for a range of physiological processes in the body. When it comes to sleep, particularly important nutrients include B-vitamins (especially vitamin B₆), zinc, vitamin E, copper, iron, calcium, magnesium and the amino acid tryptophan. These are required for the production of important hormones and neurotransmitters necessary in initiating and maintaining sleep.

• Medical conditions- sleep disorders can be caused by a range of medical and physical conditions. As depicted in table 2, sleep problems are associated with cardiovascular, hormonal, respiratory and musculoskeletal disorders, just to name a few.

• Chronic pain- people suffering from chronic pain conditions often suffer from sleep disturbances.

• Physical inactivity- lack of physical activity in the form of exercise and general physical movement can lead to sleep disorders. Exercise is important in reducing muscular tension, improving mental health and balancing mood-enhancing brain chemicals. Balance is the key when it comes to exercise as too much exercise or exercising late in the evening can also be detrimental to sleep.

• Food allergies- allergies and intolerances to certain foods can contribute to sleep disturbances. The most common food culprits are yeast, wheat, corn, milk and other dairy products, egg whites, tomatoes, soy, shellfish, peanuts, chocolate, and food dyes and additives. Food intolerances can trigger the release of histamine in the brain, which can disturb a person's biochemistry and, in some cases, lead to sleep disturbances. Food allergies can also disrupt blood sugar balance.

• Digestive disturbances- digestive problems can lead to symptoms such as heartburn, stomach bloating, stomach pain, diarrhoea, constipation and flatulence which can all disrupt sleep patterns. Digestive problems can also lead to nutrient imbalances, cause inflammation, and disrupt normal daily variations in important sleep hormones such as melatonin.

• Impaired liver detoxification- The liver is essential for detoxification and the removal of toxins from the body and is one of the causes of insomnia that is often overlooked. When it is not working optimally, the body can become excessively toxic which has been shown to disturb sleep.

• Excess toxin exposure- Excess metals such as mercury, lead, copper, thallium, and arsenic can lead to insomnia, fatigue, and lethargy. Because the level of metals that a body can handle varies significantly across people, body stores in one person may trigger numerous symptoms in one person and none in another. Ultimately, the goal is to reduce levels of toxic metals in ALL people.

• Exposure to electromagnetic fields (EMFs)-extremely low frequency EMFs can disrupt circadian rhythms, diminishing the pineal gland's ability to produce melatonin and other important hormones. Melatonin is a hormone important in sleep regulation. EMFs can be generated from electrical power lines, household appliances, computers and electronic devices.

• Environmental pollution- toxic household chemicals and disruptive noise levels can impair melatonin production, nullify attempts at relaxation and interfere with sleep.

• Hormonal Imbalances- imbalances in the sex hormones oestrogen, progesterone, and testosterone can impair sleep in both men and women. Excess or insufficient levels of thyroid hormones can also be detrimental to sleep.

• Structural Imbalances- sleep can be disrupted by structural imbalances, particularly of the spine. Such conditions block the flow of nerve impulses, either causing pain that keeps a person awake at night or impinge on the nervous system's ability to send sleep signals.

The above causes of insomnia need to be identified if you are to overcome your sleep problems effectively. Consultation with a practitioner knowledgeable in the area of sleep disorders is important as there are fortunately a number of effective treatments for sleep disorders.

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