To put it simply, insomnia is not being able to sleep. It is a common sleep disorder and is usually a symptom of another underlying disorder or problem.

There are various causes of insomnia. Different people have different reasons for their sleep problems and most of the time they can be cured by making a few lifestyle changes or changing a few habits.

For example, drinking too much caffeine during the day through tea or coffee could be the cause of your insomnia, which you can solve by cutting down on these beverages.

Insomnia is of two types: Acute and chronic. Acute insomnia is of short duration and the chronic form tends to stay for a long period. The causes of both the acute and chronic types have also been separately explained.

Why you cannot sleep? Causes


Certain drugs you may be taking for some other health ailment may cause disturbances in your sleep as a side effect.

Such medications include psychotic drugs, herbs, caffeine, cocaine, antihistaminics, amphetamines, synthetic broad-spectrum antibiotics, pain relievers, diuretics, high blood pressure medication, and corticosteroids.

Consult your physician if you are on any of these drugs and have difficulty sleeping.

Caffeine drinks

Coffee, tea, cola, and other caffeinated drinks are nervous system stimulants. Drinking them in the evening will keep your brain stimulated and you may have difficulty falling asleep.

Sleep disorders

Sleep disorders such as sleep apnea and narcolepsy cause fragmented sleep and insomnia. Seek medical help.

Restless Legs Syndrome

Restless Legs Syndrome is a neurological disorder in which there is an irresistible urge to move the affected body parts (usually the legs) to stop odd uncomfortable sensations such as tingling, itching, crawling, burning, pulling, aching. This off-and-on urge interferes with your sleep. Seek medical help.

Chronic pain

Pain caused by an injury or a chronic disease such as Osteoarthritis will not allow you to sleep.

Hormonal changes

Hormonal imbalance in women such as which occurs before menstruation and during menopause may disrupt your sleep. During menopause, night sweats and hot flashes are common and can keep you awake. Insomnia is common in pregnancy.

Stress and anxiety

Tension, stress, anxiety, and fear, which occur due to certain life events will not allow you to sleep. If this is a long-standing problem, see your psychiatrist. Chronic stress wreaks your hormonal balance (cortisol and melatonin), which can lead to insomnia.

Mental disorders

Mental disorders such as depression, bipolar disorder, anxiety, schizophrenia, post-traumatic stress disorder, and dementia are common causes of sleeplessness.

Approximately, half of the patients who are diagnosed with insomnia suffer from psychiatric disorders. Seek professional help.


Excessive alcohol intake or alcohol withdrawal are conditions that prevent proper sleep. Alcohol may help you to fall asleep but interferes with the stages of sleep due to which you may wake up in the middle of the night.

Alcoholics who give up alcohol suffer from alcohol withdrawal symptoms of which insomnia leads the group. It can last for months. Professional help can play a major role in curing such people.

Long flight travel

Long flights across several time zones can cause a disturbance in your body’s circadian rhythm and deprive you of proper sleep due to jet lag. However, this is transient and you get back to your normal rhythm within a couple of days.

Changing work shifts

Night shift work will have a negative effect on your sleep. A disturbance in your body’s internal circadian physiology is responsible for the problem of getting proper sleep.

Medical conditions

Certain medical conditions that associate you with insomnia include hyperthyroidism, rheumatoid arthritis, asthma, allergies, Parkinson’s disease, acid reflux, kidney disease, cancer, sleep apnea, and Alzheimer’s disease.

Poor sleep environment

Poor sleep hygiene such as noise, too much light in your bedroom, or a bad mattress can prevent you from falling asleep. Adopt proper sleep hygiene measures. Cut off the noise and artificial light from the bedroom and have a properly soft and firm mattress.

Change of environment

Changes in the physical environment like moving to a new place or starting a new job can cause difficulty in going to sleep.

Physical exercise

Physical exercise before bedtime can cause increased sleep onset latency. Exercise is necessary but it is best to do it in the morning or afternoon. However, if you have time constraints, exercise at least four hours before bedtime. Aerobic exercises such as brisk walking, jogging, and swimming will make you go to sleep faster and help get a good deep sleep.

Heavy smoking

Heavy smoking causes insomnia because the heavy smoker experiences nicotine withdrawal within a few hours every time he goes to sleep.

Watching television

Watching television or working on a computer before bedtime disturbs the circadian rhythm (biological clock) of the body because of the bright light coming off the screen. Avoid both these practices at least an hour before going to sleep.

Afternoon siesta

A long afternoon siesta can prevent you from easily falling asleep at night. A short nap of about 20 minutes is okay but you should avoid a long afternoon sleep, which will disturb your sleeping at night.

Of the above reasons due to which you can’t sleep, some of them cause acute insomnia (less than 30 days), and some are associated with chronic insomnia (more than 30 days). Let’s segregate them for both these conditions.

Causes of Acute Insomnia

The following are the reasons that can cause acute insomnia:

  • Stressful situations such as those caused by temporary occupational conditions, an illness, or a financial setback
  • Environmental disturbance during sleep hours such as noise
  • Death or sickness of a loved one
  • Change in work shifts
  • Medications that are taken on a temporary basis such as those for colds, allergies, and asthma

Causes of Chronic Insomnia

  • Chronic illnesses causing chronic pain or stress such as joint disorders, cancer, acid reflux, heart disease, HIV/AIDS, hyperthyroidism, and stroke.
  • Certain medications are required to be taken over prolonged periods such as antidepressants, antiepileptics, bronchodilators, beta-blockers, steroids, CNS stimulants, oral contraceptives, etc.
  • Sleep disorders such as sleep apnea and restless legs syndrome.
  • Psychiatric disorders such as schizophrenia, bipolar disorder, and major depression
  • Abuse of substances such as alcohol, caffeine, stimulants, or their withdrawal can cause chronic insomnia.

Risk factors

Advanced age

Some elderly people find it difficult to go to bed possibly due to medication or an underlying disease. Although elderly people can do 6 hours of sleep, more than half the people over the age of 60 years suffer from some degree of insomnia.


Women are at a greater risk of suffering from insomnia because of hormonal changes during the menstrual cycle, menopause, and pregnancy.

Chronic diseases

According to the Center for Disease Control and Prevention (CDC),

“Notably, insufficient sleep has been linked to the development and management of a number of chronic diseases and conditions, including type 2 diabetes, cardiovascular disease, obesity, and depression.”


Stressed-out times can prevent you from falling asleep or getting enough sleep. Short-term stress can lead to acute insomnia while long-term stress can cause your insomnia to become chronic.

Shift duty

If your job entails working in shifts, then you are bound to have sleep problems.

Whatever the causes, insomnia can have a negative impact on the health and life of the person. Seeking professional help and adopting corrective measures is a must.