We offer two different oxygen treatments. They are not interchangeable, the evidence behind them is not comparable, and they are used for different things.
High-flow normobaric oxygen — first-line for cluster headache
Strong evidence
One hundred percent oxygen, delivered at high flow through a non-rebreather mask, breathed for fifteen to twenty minutes at the onset of an attack. “Normobaric” simply means at ordinary room pressure — you sit in a chair and breathe through a mask.
This is a first-line abortive treatment for cluster headache and it is one of the genuinely unusual treatments in headache medicine: highly effective for the right patient, and with essentially no systemic side effects, no interactions and no ceiling on how often it can be used. A randomized controlled trial published in JAMA in 2009 established that high-flow oxygen aborts cluster attacks substantially more often than air within fifteen minutes, and it has been a guideline-recommended treatment since.
It has to be actual high-flow oxygen through a non-rebreather. A nasal cannula at a few litres per minute does not reproduce the effect, which is the single most common reason someone tells us “oxygen didn’t work for me.”
It does not treat migraine. If your diagnosis is migraine, this is not the treatment for you and we will say so.
Hyperbaric oxygen (HBOT)
Limited evidence
Hyperbaric oxygen is different in kind, not just in degree: you are enclosed in a chamber and the ambient pressure is raised above atmospheric, which dissolves considerably more oxygen into the blood than breathing oxygen at room pressure can.
We will be straight about where this stands. Systematic reviews of hyperbaric oxygen for headache have found some evidence that it can relieve an acute migraine attack, but the trials are small, older, and of low methodological quality, and reviewers have consistently declined to recommend it as routine acute treatment. There is no good evidence that it prevents future attacks, and no good evidence supporting it for cluster headache, where normobaric oxygen already works well and costs a fraction as much in time and money.
That is not a reason it is never appropriate. It is a reason it should not be anyone’s first option for a headache, and a reason we will talk you out of it if a better-supported treatment has not been tried. If you have been offered hyperbaric oxygen for migraine somewhere that did not tell you the evidence is thin, that is worth knowing.
Which one you need
If you have cluster headache, you want high-flow normobaric oxygen, and you likely want a home setup so you can use it at the first sign of an attack rather than driving somewhere. We can start it here and arrange the prescription.