Some examples of conditions related to insomnia include chronic pain, cancer, diabetes, heart disease, asthma, gastroesophageal reflux disease (GERD), overactive thyroid, Parkinson's disease, and Alzheimer's disease. The first symptom of severe depression, for example, may be insomnia. People with bipolar disorder, anxiety, or other mood disorders also often have insomnia. Disorders in which pain is a constant companion, such as arthritis and fibromyalgia, can cause insomnia.
Similarly, medical problems that cause itching can disrupt sleep. Medical conditions such as acid reflux, thyroid problems, strokes, or asthma. Substances such as alcohol and nicotine travel, especially between time zones. Kuppermann and collaborators23 found that people who reported having a current sleep problem were more likely than people who slept well to have lower work performance and to be absent from work during the past month due to health problems.
In addition, average total health care costs were 60% higher in the insomnia group compared to controls. Research has shown that, among the daytime consequences of insomnia, the increase in accidents represents the greatest health risk. Don't forget that there are other reasons why you might not get the sleep you need; besides poor sleep hygiene, you may suffer the side effects of medications used to treat your medical conditions, for example. Diseases such as psoriasis and eczema can cause your skin to burn and itch so much that you can't think about anything else.
Several risk factors associated with the increased prevalence of chronic insomnia include older age, female gender, and comorbid medical and psychiatric conditions. Insomnia can be triggered by several possible factors, such as worry and stress, underlying health conditions, and alcohol or drug use. Going around and waking up repeatedly is as bad for your health as not being able to fall asleep. Patients with insomnia showed significantly higher metabolic rates (measured at intervals throughout the 24 hours a day) than healthy controls.
The close association between insomnia and depression is probably related to the common underlying physiopathological mechanisms for the regulation of sleep and mood that make the individual vulnerable to both conditions. Discovering and treating an undiagnosed condition, or being more proactive about treating a condition you already know you have, can do wonders for your nighttime sleep. Older people may be less likely to sleep soundly because of age-related body changes and because they may have medical conditions or take medications that disturb sleep. A 36-hour study37 found that the average heart rate increased and variability decreased at all stages of sleep in patients with insomnia compared to those who slept normally and healthy.