Overview
Insomnia is a sleep disorder characterised by difficulty falling asleep, staying asleep, or getting restorative sleep, despite having adequate opportunity to do so. It can be acute (short-term, linked to specific stress) or chronic (lasting more than three months, at least three nights per week). Insomnia affects both the quantity and quality of sleep and can have significant effects on daytime functioning and overall health.
Causes and risk factors
The following factors are associated with the development of Insomnia:
- Stress, anxiety, and worry
- Depression and other mental health conditions
- Poor sleep habits and irregular sleep schedule
- Stimulants: caffeine, nicotine
- Alcohol — disrupts sleep architecture
- Blue light from screens before bed
- Environmental factors: noise, light, temperature
- Medical conditions: pain, reflux, sleep apnoea, restless legs
- Certain medications
- Shift work and jet lag
- Ageing — sleep patterns change
- Menopause — night sweats
Signs and symptoms
Common signs and symptoms of Insomnia include:
- Difficulty falling asleep at night
- Waking during the night and difficulty returning to sleep
- Waking too early
- Not feeling rested after sleep
- Daytime tiredness and fatigue
- Difficulty concentrating or remembering
- Irritability, depression, or anxiety
- Increased errors or accidents
- Ongoing worry about sleep
- Tension headaches
Diagnosis
Insomnia is typically diagnosed through a combination of medical history, physical examination, and appropriate investigations such as blood tests, imaging, or specialist review, depending on the specific condition and presentation. Your doctor will consider all relevant symptoms and risk factors before making a diagnosis.
Treatment options
Treatment approaches for Insomnia may include:
- Cognitive behavioural therapy for insomnia (CBT-I) — most effective long-term treatment
- Sleep hygiene: regular sleep schedule, dark/quiet/cool bedroom, no screens before bed
- Stimulus control: only use bed for sleep and sex
- Sleep restriction therapy
- Relaxation techniques: progressive muscle relaxation, meditation
- Short-term medications: z-drugs (zopiclone), melatonin
- Treating underlying conditions
- Limiting caffeine after midday and alcohol
Prevention
Consistent sleep schedule, limiting screens before bed, regular exercise (not too close to bedtime), limiting caffeine and alcohol, creating a calm sleep environment.
Complications
If left untreated or poorly managed, Insomnia can lead to complications including:
Depression and anxiety, impaired cognitive function, immune dysfunction, weight gain, increased risk of accidents, and cardiovascular problems.
Sources and references: This article is written in accordance with NHS UK, WHO, and Mayo Clinic clinical guidelines. It is reviewed for accuracy by the SymptomSense content team. ICD-10 code: G47.0. Last reviewed June 2026.