Sleep Apnoea: Why You Wake Tired After Eight Hours

Dozens of breathing interruptions an hour, none of which you remember. The tiredness is the only clue most people get.

What is happening

During sleep, muscle tone in the upper airway falls. In obstructive sleep apnoea it falls enough that the airway collapses, blocking airflow despite continued respiratory effort.

Oxygen saturation drops. Carbon dioxide rises. Eventually the brain triggers a brief arousal that restores airway muscle tone, breathing resumes with a gasp or snort, and the cycle repeats. This can happen dozens of times an hour in moderate to severe cases.

The arousals are typically too short to reach conscious memory. The person reports eight hours in bed and wakes exhausted, with no explanation.

The two harms

Fragmented sleep architecture. Restorative sleep requires sustained periods in deeper stages. Repeated arousal prevents that regardless of total time in bed, which is why duration and quality diverge so sharply here.

Intermittent hypoxia. Repeated cycles of desaturation and reoxygenation generate oxidative stress and are associated with vascular effects, elevated blood pressure, and increased cardiovascular risk over time. This is the part that makes untreated apnoea more than a tiredness problem.

Signs worth acting on

• Loud habitual snoring, particularly with witnessed pauses.
• Waking unrefreshed despite adequate hours in bed.
• Daytime sleepiness — falling asleep when inactive, in front of the television, or dangerously while driving.
• Morning headaches.
• Waking with a very dry mouth or sore throat.
• Waking repeatedly to urinate.
• Difficulty concentrating, irritability, low mood.
• Newly difficult-to-control blood pressure.

Why it is missed so often

The most common assumption is that apnoea requires obesity. It is a risk factor, and a substantial one, but the condition occurs in people of entirely normal weight where anatomical factors — a narrow airway, large tonsils, a receding jaw, nasal obstruction — are the primary contributors.

It is also substantially underdiagnosed in women, who more often present with fatigue, insomnia and low mood rather than the classic loud-snoring picture, and are correspondingly more likely to be assessed for depression instead.

And the person with the condition is the one least able to observe it. Most diagnoses start with a partner's complaint.

Diagnosis and treatment

Diagnosis is by sleep study, either in a laboratory or increasingly with a home testing device. It is not diagnosed by symptom questionnaire alone, though questionnaires are used for screening.

CPAP is the standard treatment and is effective. Adherence is the main practical challenge, and it is worth persisting through the adaptation period because the benefits — daytime alertness, blood pressure, cardiovascular risk — depend on consistent use.

Alternatives for milder cases include mandibular advancement devices, positional therapy, weight loss where relevant, and surgery in specific anatomical situations.

What supplements do not do

No supplement treats sleep apnoea. It is a mechanical airway problem requiring mechanical or surgical solution, and anything marketed as a supplement alternative to CPAP should be disregarded.

What is reasonable: addressing nasal congestion and upper airway inflammation may improve comfort and CPAP tolerance, and treating coexisting reflux can reduce airway irritation. These are adjuncts to diagnosis and treatment, never substitutes.