Dr Amir Khan, an NHS GP with a large social media following, has explained why many people wake up between 2am and 4am. He says there is a biological reason behind this common phenomenon, involving the body's natural stress hormone cortisol.
According to Dr Khan, around 2-4am, cortisol levels start to rise in preparation for waking up. This normal hormonal shift can tip someone who is already stressed or anxious into wakefulness. Additionally, blood sugar levels can dip during the night, especially after alcohol, late meals, or chronic stress, causing the body to release adrenaline and wake suddenly with a racing heart.
Psychological factors also play a role. At 3am, with no distractions, the brain's threat system becomes louder. The amygdala, which processes fear, is more reactive when sleep-deprived, making worries feel catastrophic. Hormones can also contribute, particularly in perimenopause and menopause, where fluctuating oestrogen affects temperature regulation and sleep stability.
Dr Khan emphasised that waking briefly at night is normal and that the problem is often anxiety about being awake. He suggested gentle breathing, avoiding clock-watching and screens, and keeping evenings calm to help. The NHS recommends good sleep hygiene, including consistent bedtimes and wake-up times, and notes that a few sleepless nights are usually not a concern unless they start affecting daily life.
