Morning Headaches and Sleep Apnea
Twenty-nine percent of people sent for a sleep study report them, and they improve dramatically with treatment — prevalence fell from 53% to 16%. What they are not is a measure of how severe your apnea is.
Waking with a headache several mornings a week is one of the more useful symptoms in this whole area, because it is specific enough to act on and common enough to be worth asking about.
It is also routinely misused as a severity gauge, which the evidence does not support.
How common it is
A retrospective study of 1,131 patients referred for polysomnography because apnea was suspected found morning headaches reported by 29% of them.
The factors that predicted them are revealing. In a logistic regression, the probability rose with:
| Factor | Odds ratio (95% CI) |
|---|---|
| Female sex | 1.38 (1.08–1.75) |
| History of hypertension | 1.25 (1.06–1.46) |
| Complaint of unrefreshing sleep | 1.42 (1.19–1.70) |
| Choking at night | 1.25 (1.05–1.49) |
| Falling total sleep time | 0.872 per hour (0.76–0.99) |
Notice what is missing from that list: the apnea-hypopnea index and the blood-oxygen measures were not what predicted morning headache. The symptom travelled with sex, blood pressure, unrefreshing sleep and nocturnal choking — not with the number that defines apnea severity.
It responds well to treatment
A 2023 study of 116 patients, all of whom received positive airway pressure therapy for at least three months, measured what happened.
Morning headache prevalence fell from 53.4% to 16.4%, and severity from 1.92 to 0.86, all at P<0.001. The improvement was largest in the people who had headaches to begin with, which is what you would hope.
Two further findings from that study tie the picture together:
Sleepiness and headache travel together. Epworth scores were significantly higher in the group with morning headaches (10.90 vs 8.13, P=0.003), and the reduction in daytime sleepiness correlated with the improvement in headache after treatment (r=0.503, P<0.001).
Severity category mattered, individual measurements did not. Headache severity was higher in the severe apnea group than in the mild-to-moderate group (2.16 vs 1.50, P=0.027) — yet the individual polysomnographic parameters did not differ according to whether someone had headaches at all.
So apnea severity influences headache at the population level while failing to predict it in any particular person. That is a common pattern in this field and it is why symptoms and sleep studies answer different questions.
Evidence tier 1 that morning headache is associated with sleep apnea and improves substantially with PAP therapy. Tier 3 as a severity indicator — it does not track AHI or oxygen measures.
The relationship runs both ways
It is not only that apnea causes headaches. A nationwide population-based study found an increased risk of sleep apnoea among people with primary headache disorders — so having migraine or another primary headache condition raises the likelihood of apnea rather than merely resembling it.
Practically, that means a headache history is a reason to screen for apnea, not a reason to assume the headaches explain themselves.
What to do with this
If you wake with headaches several mornings a week, say so when you are assessed. It is one of the symptoms with a good treatment response, and it belongs alongside the others. How to describe your symptoms usefully.
Do not use it to judge how bad your apnea is. Having morning headaches does not mean severe apnea, and not having them does not mean mild. Only a sleep study answers that. What testing involves.
Do not assume apnea is the cause either. Morning headache has plenty of other explanations — bruxism, medication overuse, caffeine withdrawal, alcohol, poorly controlled hypertension, and primary headache disorders. The 29% figure comes from people already suspected of apnea, which is a selected group.
Expect improvement if you are treated, and tell someone if it does not come. Prevalence dropping from 53% to 16% is a large effect. If you are using PAP properly and the headaches persist, that is information worth taking back rather than tolerating.
And treat it as a prompt rather than a diagnosis. The signs that most warrant testing remain witnessed breathing pauses, gasping or choking arousals, waking unrefreshed after adequate hours, and daytime sleepiness that more sleep does not fix. Snoring versus apnea, and what untreated apnea accumulates.