Why the confusion exists
Both insomnia and sleep apnea produce daytime fatigue, poor concentration, and irritability. Up to 40 percent of people with sleep apnea also report insomnia symptoms, and many patients spend years treating one when the real problem is the other.
Insomnia: the core signature
Trouble falling asleep, staying asleep, or waking too early, despite adequate opportunity. Sleep onset latency often exceeds 30 minutes. The brain feels 'on' at bedtime. Sleep quality varies widely night to night.
Sleep apnea: the core signature
You fall asleep fine. The problem happens unconsciously: airway collapses, oxygen drops, brain micro-arouses to restart breathing. You wake gasping or with a dry mouth, feel unrefreshed regardless of hours slept, and a bed partner reports loud snoring with pauses.
Five questions that point to apnea
Do you snore loudly? Has anyone witnessed you stop breathing? Do you wake unrefreshed even after 8 hours? Do you have high blood pressure? Is your neck circumference over 17 inches (men) or 16 inches (women)? Three or more yes answers warrants a sleep study.
Five questions that point to insomnia
Does your mind race at bedtime? Do you watch the clock at night? Does the bedroom feel like a stress trigger? Did symptoms start during a stressful period? Do you sleep better away from home? Three or more yes answers points to insomnia.
When you have both
Treat the apnea first. CPAP plus CBT-I in parallel resolves both faster than treating either alone. Insomnia that started after the apnea is often a learned response to disrupted sleep and fades when oxygenation is restored.
FAQ
Can a home sleep test diagnose both? It can diagnose apnea reliably; insomnia is a clinical diagnosis from history and a sleep diary. Will CPAP cure my insomnia? Only if your insomnia is secondary to apnea. Primary insomnia still needs CBT-I.