Dr Amir Khan has shed light on why many of us find ourselves waking at a particular hour during the night. The NHS GP, who boasts a substantial social media presence, shared a video with his followers explaining that 'it is actually common and normal'.

He revealed that countless people wake between 2am and 4am - and there is a 'biological reason' behind it. According to him, it's down to a combination of your brain beginning its early preparations for the day ahead and cortisol - your 'natural stress hormone'.

WebMD describes cortisol as your 'body's main stress hormone. It works with certain parts of your brain to control your mood, motivation, and fear'. The hormone is crucial in regulating sleep patterns and when you naturally wake.

However, Dr Khan highlighted that psychological elements can also come into play. If you're feeling stressed, drifting back to sleep can prove difficult due to the absence of distractions in your bedroom at that hour, reports Surrey Live.

Dr Khan explained: "Have you ever noticed that you fall asleep just fine and then suddenly you're awake at 3am staring at the ceiling overthinking your entire life? Well, there's actually a biological reason for that.

"Around 2-4am, your body is in a very particular phase of its sleep cycle. Cortisol, your natural stress hormone, starts to rise in preparation for waking up. It's completely normal, but if you're already stressed, anxious, or running on empty, that small hormonal shift can be enough to tip you into wakefulness.

"At the same time, your brain is more vulnerable. During the night, especially in the early hours, blood sugar levels can dip slightly. If they drop too low, which is more likely if you've had alcohol, eaten very late, or are under chronic stress, your body releases adrenaline to compensate. That little surge can wake you up suddenly with a racing heart or a sense of alertness.

"Add in the fact that at 3am there are no distractions, no emails, no noise, just you and your thoughts, and your brain's threat system becomes louder. The amygdala, the part of the brain that processes fear, is more reactive when we're sleep-deprived. So worries that feel manageable at 3pm can feel catastrophic at 3am."

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What does the NHS say?

The NHS emphasises that sleep difficulties are common and can stem from various causes. It notes that experiencing a few sleepless nights consecutively isn't typically something to worry about.

However, it did recognise that persistent sleep deprivation can lead to complications. The health service recommends that a healthy adult generally requires between 7-9 hours of sleep nightly - though this can vary based on age, health status, and other circumstances.

Youngsters, children, and infants require more rest due to their ongoing development. The NHS states: "Sleep problems are common, and the reasons we struggle to sleep are likely to change throughout our lives, for instance, illness, work, or having a baby are possible causes.

"A few sleepless nights are usually nothing to worry about, but it can become an issue if a lack of sleep starts to affect your daily life."

Hormones

Dr Khan explained that hormones, particularly during perimenopause and menopause, can also play a role. He stated: "Hormones also play a role. In perimenopause and menopause, fluctuating oestrogen affects temperature regulation, cortisol sensitivity, and sleep stability.

"That's why so many women report early morning awakenings and poor sleep itself becomes part of the cycle. The more you worry about waking up, the more likely you are to wake up."

How to fall asleep again?

Dr Khan added: "Now, waking briefly in the night is actually normal. We all cycle through lighter sleep every 90 minutes. The problem isn't waking up, it's the anxiety about being awake.

"So gentle breathing, avoiding clock-watching and screens, and keeping evenings calm and alcohol light can really help. So if you're awake at 3am, it doesn't mean you're broken, it just means your biology is doing what biology does, and we just need to help it along a little bit."

The NHS suggests that good sleep habits, such as maintaining a consistent bedtime and wake-up time, can improve our sleep quality. This regular sleep routine is often referred to as sleep hygiene.

A proper sleep routine involves establishing a regular wind-down time and incorporating relaxation techniques. Maintaining consistent bedtimes and wake-up times is another beneficial habit, ideally keeping the same schedule every day, weekends included.

Experts recommend switching off electronic devices at least an hour before bed, as smartphones, tablets and computers emit blue light which disrupts sleep. For those struggling to nod off, reading, listening to calming music or podcasts, or trying sleep meditation can prove helpful.

Your bedroom environment matters too – it should be quiet, dark and cool, with silence being essential for quality rest. A nutritious diet and regular physical activity can promote relaxation and improved sleep quality.

The reverse holds true as well: poor eating habits and insufficient exercise can interfere with sleep. That said, it's best to avoid exercising within 90 minutes of bedtime.