Insomnia

Insomnia (insomnia): Causes and mechanisms of sleep disturbance

Insomnia, or insomnia, is a sleep disorder characterized by persistent difficulties falling asleep, maintaining sleep, or its quality, despite having sufficient time and conditions for sleep. It is not just a single "bad night", but a chronic problem that significantly affects daytime well‑being, causing fatigue, irritability and concentration problems. Insomnia can be a standalone condition or a symptom of other medical or mental disorders.

What happens in the brain during insomnia?

At the core of chronic insomnia lies a state of hyperarousal (hyperarousal). This means the person's nervous system remains in a "fight‑or‑flight" mode even when it should relax and fall asleep. The brain cannot shift from an activation mode to a braking mode. This may be related to an imbalance of neurotransmitters that regulate sleep‑wake cycles (e.g., serotonin, GABA, norepinephrine).

Main causes and risk factors

The causes of insomnia are rarely isolated; they usually involve a combination of factors.

• Psychological factors (most common cause):
  • Stress: Acute or chronic stress related to work, relationships, or health.
  • Anxiety disorders and depression: Insomnia is one of the key symptoms of these conditions. Anxiety interferes with falling asleep, and depression often causes early morning awakenings.
• Behavioral factors (poor sleep hygiene):
  • Irregular sleep and wake schedule.
  • Use of gadgets (blue light suppresses melatonin production) before bedtime.
  • Consumption of stimulants (caffeine, nicotine) in the latter part of the day.
• Medical factors:
  • Chronic pain.
  • Endocrine disorders (e.g., hyperthyroidism).
  • Sleep apnea or restless legs syndrome.

In women, insomnia is often linked to hormonal fluctuations, especially pronounced during pregnancy (pregnancy insomnia) and menopause.