There are many causes of insomnia. The following are some of the more common causes:
1. Pseudo-insomnia. This is probably the most common cause in the normal population. These people believe they cannot sleep because of one or more of the above mentioned reasons. Their confidence to sleep is gone, and they become worried as the evening approaches since they predict they will not sleep. Because they experience insomnia in bed, some develop a phobia about their beds, as they can sleep anywhere and at any time except in bed. They may be quite happy sleeping on a sofa or in front of the television, but when they are in their beds at night they are wide awake and feel distressed.
2. Biological clock related insomnia. We all have a biological clock within us. Sometimes we have to reset out biological clock abruptly; for instance, because of jet lag or a change in shift duties, and the clock is thrown out of phase. The biological clock governs a number of biological functions in the body; the most important is the sleep pattern. The other functions are body temperature, hormonal balance, metabolic rate, urine output, stomach and bowel activity, and so on. Each biological function follows the biological clock differently, and any sudden changes to the clock throw them out of phase with each other. Besides not being able to sleep, we feel below par and are unable to function normally.
3. Situational insomnia. This is normally transient and is precipitated by some situation that a person is experiencing. Anxiety, stress, and worry of what is going to happen are typical causes of insomnia. Stress is a common cause of insomnia.
4. Physical illness. It is a fairly common practice for the sister in charge of a hospital ward to ask the resident doctor to prescribe sleeping pills for the patients just in case they cannot sleep. This is a much more common practice in nursing homes. There are two reasons why sleeping pills are prescribed in hospital. The first is that it is reasonable not to be able to sleep in hospital. You are sick and in a totally new bed in a new environment with a new routine. On top of all this there is the additional stress of your own physical illness and not knowing its outcome. The second reason is that if some patients are not sleeping they may interfere with the other patients and, in the end, no one gets any sleep.
5. Pain. We all experience pain at some stage in our lives, whether it is toothache, headache, stomach-ache, or whatever. The pain we feel drags us down, we feel awful, our whole routine is ruined. Chronic pain is even worse, as there is no escape; the pain is with the sufferer all the time. People who suffer from chronic pain may find sleep the only escape, but if they have insomnia there is no escape at all.
6. Drug-withdrawal insomnia. It is now recognized that the modern sleeping pill is effective for
about two weeks only. These pills supress REM sleep. When the pills are stopped, the sleeper experiences a rebound of excessive REM sleep. This means the sleeper will have an excessive number of dreams and sometimes nightmares. This will be experienced as disruptive sleep and insomnia. The person who experiences drug-withdrawal insomnia believes that his innate ability to sleep is lost, for once he stops taking the pills he cannot sleep anymore. In fact, of course, he has not lost his ability to sleep. It is just that the symptom of drug withdrawal is insomnia. It is a common experience for a patient to see his doctor and say, 'I ran out of sleeping pills two nights ago and I cannot sleep at all. I guess I do not know how to sleep anymore. Please prescribe me another 50 tablets'. This should of course be rephrased as, 'I ran out of sleeping pills, and I cannot sleep because I am addicted to them, but once the withdrawal effect passes I will be sleeping again'. Ideally sleeping pills should not be stopped suddenly, but rather the dosage reduced gradually and finally stopped.
7. Excessive daytime sleepiness or EDS. This includes narcolepsy and sleep apnoea. Narcolepsy is abnormal sleep attacks and sleep apnoea is frequent waking at night because of an inability to breathe. Sufferers fall asleep easily in the daytime and most of them do not have the distress of not sleeping at night; hence their chief complaint is normally not insomnia.
8. Mental illness. Insomnia is a common symptom of mental illness, but frequently there are many other symptoms at the same time. This book is not written for sufferers of mental illnesses, as they always need the care of professionals. People with these conditions should not stop their medications, as very often the medications provide the only effective treatment.