Sleep is regulated by circadian rhythms, which are the natural light-dark signals that induce sleepiness at night and alertness in the morning. Early waking is the undesirable state of waking at 3 am or 4 am and being unable to fall back asleep. This condition is common in older adults, as aging affects their circadian rhythm and reduces their overall sleep requirements. Persistent early waking leads to fatigue, sleep deprivation, and reduced daytime focus, significantly impacting daily life and work quality.

**Insomnia**

The primary cause of early morning waking is insomnia, which is characterized by difficulty maintaining continuous sleep throughout the night. While these awakenings can occur multiple times, they tend to be more frequent in the second half of the night, often after 2 am, as the body's ability to sleep gradually diminishes towards morning.

Insomnia can be addressed through various methods, depending on its underlying cause. Practicing good sleep hygiene is crucial: going to bed and waking up at the same time daily, limiting electronic devices in the evening, and ensuring the bedroom is cool, quiet, and moderately lit all contribute to improving sleep quality.

Insomnia is a cause of waking earlier than usual. *AI-generated image*.

**Anxiety and depression**

Psychological disorders, such as depression, anxiety disorders, or prolonged stress, are linked to early morning waking. These conditions can cause individuals to wake up several hours earlier than intended. They lead to an imbalance in neurotransmitters that regulate mood, causing brain regions associated with arousal to become overactive and stimulated, which results in early waking. Individuals experiencing these symptoms should consult a doctor to determine the cause of their depression or anxiety and receive appropriate treatment, preventing adverse effects on their sleep quality.

**Sleep apnea**

Obstructive sleep apnea syndrome is another factor contributing to early morning waking. Throughout the night, sleepers typically cycle through various sleep stages. In the second half of the night, rapid eye movement (REM) sleep, the dreaming state, becomes more dominant. Sleep apnea is more likely to occur during REM sleep when the muscles lining the airway become actively paralyzed, disrupting normal breathing patterns. These sleep apnea episodes often cause individuals to awaken momentarily and are particularly common in the early morning hours.

**Circadian rhythm and aging**

Some individuals naturally tend to wake up early in the morning due to their preference, often going to bed as early as 9 pm. This represents a healthy circadian rhythm, provided they consistently achieve 7-8 hours of sleep each night, offering numerous health and cognitive benefits. However, early waking is also a common occurrence in older adults. As people age, their ability to maintain continuous, uninterrupted sleep gradually declines. This can result in more fragmented sleep and a reduction in total sleep time.

By Anh Chi (According to Very Well Health)