What Is the Main Cause of Insomnia?

Lifestyle and environmental issues like stress, drug and alcohol use, and shift work may cause insomnia. Medications, mental, hormonal, or neurological disorders may also be a cause of sleeplessness.

Insomnia is the most common type of sleep disorder and it involves problems falling asleep or staying asleep despite adequate opportunity to do so.

There are three types of insomnia:

• Short-term insomnia disorder
• Chronic insomnia disorder
• Other insomnia disorder (symptoms that do not meet the criteria for the other two types of insomnia)

Symptoms and signs of insomnia include the following:

• Difficulty falling asleep or staying asleep
• Variable sleep
• Daytime fatigue or sleepiness
• Forgetfulness
• Difficulty concentrating
• Irritability
• Anxiety
• Depression
• Decreased motivation or energy
• Increased errors or accidents
• Persistent worry about sleep

Insomnia may be caused by multiple factors. The main cause of insomnia is believed to be a state of mental and/or physical hyperarousal that interferes with falling asleep or staying asleep.

Causes of insomnia include:

• Changes in sleeping environment 
  • Temperature
  • Light
  • Noise
• Stress
  • Loss of a loved one
  • Loss of a pet
  • Divorce
  • Job loss
• Illnesses, especially those that cause stress or difficulty breathing
• Surgery
• Pain
• Unhealthy lifestyle habits
  • Working late
  • Playing video games
  • Using other electronic devices
  • Napping late in the afternoon
  • Sleeping in later to make up for lost sleep 
  • Using the bed for activities besides sleep
  • Diet choices 
    • Stimulants, such as caffeine
    • Alcohol
    • Heavy meals 
    • Spicy foods 
• Use of or withdrawal from some medications and illegal drugs
  • Blood pressure drugs
  • Anti-asthma medications
  • Antidepressants
• Irregular sleep habits
• Irregular sleep schedules that disrupt the circadian rhythm
  • Jet lag 
  • Shift work 
• Mental health problems 
  • Depression
  • Anxiety
  • Posttraumatic stress disorder (PTSD)
• Neurological disorders 
  • Parkinson’s disease 
  • Alzheimer’s disease
  • Attention-deficit/hyperactivity disorder (ADHD) 
  • Autism spectrum disorder
• Other sleep disorders
  • Obstructive sleep apnea
  • Restless leg syndrome 
  • Parasomnias
  • Sleepwalking
  • Nightmares
  • Sleep paralysis
• Pregnancy
  • Discomfort
  • Disrupted breathing
  • Reflux
  • Nighttime urinary frequency 
  • Restless leg syndrome
• Genetics
• Age: teenagers and elderly experience insomnia more frequently
• May not have a known cause

Sleep disorders are diagnosed with a patient history and physical exam. Tests or procedures that may be used to diagnose sleep disorders or to rule out other underlying conditions include the following: 

• Daily sleep log
• Sleep study (polysomnography)
• Record of activity and movement with a monitor or motion detector, generally worn on the wrist throughout the day and night (actigraphy)
• Home sleep apnea testing 
• Home devices that monitor breathing, oxygen saturation, position, and heart rate
• Melatonin sampling 
• Core body temperature measurements 
• Hormone tests
• Electrocardiogram (ECG) 
• Computerized tomography (CT) scan 
• Pulmonary function tests
• Magnetic resonance imaging (MRI) of the brain

Treatment for insomnia includes the following:

• Cognitive behavioral therapy for insomnia (CBT-I)
• Sleep education 
• Sleep restriction or sleep compression  
• Stimulus control 
• Sleep hygiene 
• Relaxation exercises 
• Sleep medications, both over-the-counter (OTC) and prescription