HBOT works by delivering high-concentration oxygen under pressure to boost dissolved oxygen in plasma and brain tissue. This helps when parts of the brain aren’t getting enough oxygen during headache episodes and can also modulate inflammatory and vascular processes that contribute to headaches. The strongest support for HBOT is with migraine and cluster headaches. These conditions involve vascular changes and inflammation where extra oxygen delivery and improved tissue oxygenation can help relieve pain, reduce attack severity, or lower attack frequency in some patients. The therapy can also influence the signaling pathways that drive neurovascular pain, which is why it’s considered a potential option for these headaches. Tension headaches and sinus headaches don’t have as much evidence linking them to oxygenation deficits that HBOT can correct, and their primary drivers aren’t the same vascular/inflammatory processes HBOT targets. So HBOT is not a standard or well-supported treatment for those types.