Why Can’t You Sleep? Causes, Diagnosis and Treatment of Insomnia

Adrian Mercer

Spending hours awake after going to bed, waking repeatedly during the night or opening your eyes too early in the morning can leave both the body and mind exhausted. In young people, studies, work, irregular routines and late-night phone use may contribute to the problem. Among older adults, pain, chronic illness, medication and frequent nighttime urination can interrupt sleep. Age alone, however, should not be assumed to be the cause; the underlying reasons need to be considered.

Sleep may be disrupted for a few days by stress, travel or a change in routine. But when someone has difficulty falling or staying asleep at least three nights a week, despite having enough time and a suitable environment for sleep, and the problem affects daytime functioning for three months or longer, it may be considered chronic insomnia. Daytime fatigue, irritability, difficulty concentrating and poor memory can follow. Chronic insomnia is also associated with health problems such as high blood pressure, heart disease and diabetes.

Insomnia rarely has just one cause. Stress is a major factor. Worries about studies, work, finances, family relationships, caregiving or the future can keep the mind active. Anxiety and depression can disrupt sleep, while a lack of sleep can worsen these difficulties. Fear that another sleepless night will make the next day unbearable—and repeatedly checking the clock—can make it even harder to fall asleep.

Daily routines and the sleep environment also matter. Going to bed at different times, working night shifts, taking long naps, getting little physical activity, or sleeping in a room with too much light, noise or uncomfortable temperatures can disrupt the body’s sleep-wake cycle. Watching television or using a phone or other electronic device late at night may also delay bedtime. Caffeine in tea, coffee, cola and energy drinks can remain active in the body for hours. Nicotine can interfere with sleep as well. Alcohol may initially make someone feel drowsy, but it can lead to lighter, more fragmented sleep.

Insomnia can also be a symptom of another health problem or a side effect of medication. Joint or back pain, acid reflux, asthma, heart or lung disease, thyroid problems, frequent nighttime urination and uncomfortable sensations in the legs that create an urge to move can all interfere with sleep. Loud snoring, pauses in breathing or waking up gasping for air may point to a sleep-related breathing disorder. Physical and hormonal changes during pregnancy and menopause can also affect sleep. Some medicines for colds, allergies and other conditions may disrupt sleep. Patients should discuss their medicines with a doctor or pharmacist and should not stop prescribed medication on their own.

Among teenagers and young adults, the body’s natural tendency to fall asleep later, early school or work schedules, exam and employment pressures, and late-night social media or gaming can all contribute. Teenagers aged 13 to 17 generally need eight to ten hours of sleep a day. Adults need at least seven hours, while people aged 65 and older are generally advised to get seven to eight hours.

Older adults may have lighter sleep, wake more often during the night or rise earlier in the morning. Changes in the body’s sleep-wake cycle are one reason. Joint pain, chronic illness, nighttime urination, reduced physical activity, depression and taking several medicines at once may also contribute. Persistent sleep problems should not be dismissed as an inevitable part of ageing. Older adults who snore loudly, stop breathing during sleep, feel an urge to move their legs or experience excessive daytime sleepiness should speak with a health professional.

A useful first step is to understand your own sleep pattern. For one or two weeks, record when you go to bed, when you think you fall asleep, how often you wake, when you get up, whether you nap during the day, and when you consume tea, coffee or medication. This information can help a doctor identify possible causes. Depending on the symptoms, an evaluation may include a medical history, physical examination, blood tests or a sleep study to check for thyroid problems, breathing disorders and other conditions. A sleep study is not necessary for every case of insomnia; a clinician may recommend one when another sleep disorder is suspected.

Keeping a regular schedule can help improve sleep. Try to get up at the same time every day, spend some time in natural light in the morning and engage in regular physical activity during the day. Avoid long naps or naps late in the afternoon. Keep the bedroom quiet, dark and comfortable; limit phone and other screen use before bed; avoid heavy meals late at night; and reduce caffeine, nicotine and alcohol near bedtime. If you cannot sleep, getting out of bed for a quiet activity in dim light and returning when you feel sleepy may help more than lying awake and watching the clock.

For long-term insomnia, improving sleep habits alone may not be enough. Cognitive behavioural therapy for insomnia is recommended as a first-line treatment for chronic insomnia. It helps people reduce anxiety about sleep, practise relaxation, strengthen the connection between bed and sleep, and establish a more consistent sleep schedule. It can be delivered by a trained health professional in person, in a group or, where available, remotely. Sleep advice can be useful, but clinical guidelines do not consider it sufficient as the sole treatment for chronic insomnia.

Taking sleeping pills without medical advice, or using someone else’s medication, can be risky. Some medicines can cause next-day drowsiness, dizziness, interactions with other drugs or dependence. Older adults may also face a greater risk of confusion, poor balance and falls. A clinician should decide whether medication is appropriate after considering the cause of the problem and the person’s health. Melatonin and herbal products are not safe or effective for everyone, so it is best to consult a health professional before using them.

Seek medical advice if poor sleep is affecting daily life several nights a week, continues for three months or longer, involves loud snoring or pauses in breathing, or is accompanied by uncontrollable daytime sleepiness, persistent pain, depression or anxiety. Insomnia should not be treated as a failure of willpower. It may signal a problem with habits, mental health or physical health. Identifying the cause and choosing the right treatment is the path to lasting improvement.