Imagine reclining in a chamber for 90 minutes, surrounded by pure oxygen at pressures two to three times higher than those at sea level. This is **hyperbaric oxygen therapy (HBOT)**—a long-standing medical treatment now being studied as a possible option for people living with Long COVID.
For John M.\*—a patient who has undergone dozens of HBOT sessions—this therapy offered the first real relief from debilitating symptoms. “At one point after hospitalization, my Long COVID symptoms were so bad that I could barely walk or talk. HBOT was a great tool that really assisted with my recovery,” he shared. John noticed improvements in sleep and fewer heart palpitations, and he hopes further research will expand access for others struggling with the condition.
What is HBOT?
Hyperbaric medicine has been used for decades to treat conditions such as **decompression sickness in divers, carbon monoxide poisoning, and diabetic foot ulcers**. During treatment, patients breathe 100% oxygen in a pressurized chamber. This unique combination of oxygen and pressure allows oxygen to dissolve directly into the bloodstream and reach tissues that normally have limited access.
For Long COVID, the hope is that HBOT can provide similar healing by restoring oxygen to oxygen-starved tissues and reducing persistent inflammation.
Why Might HBOT Help with Long COVID?
Long COVID patients frequently report crushing fatigue, often linked to muscles’ inability to efficiently extract and use oxygen. HBOT may help by essentially “refueling” the body, flooding tissues with oxygen in a way that normal breathing cannot.
Research also suggests HBOT could reduce **oxidative stress**—a harmful imbalance caused by free radicals that leads to chronic inflammation. In addition, studies indicate HBOT may improve mitochondrial function, reduce inflammatory cytokines, and mobilize stem cells that play a role in tissue repair. Together, these effects could address many of the overlapping problems associated with Long COVID.
What Does the Research Say?
Several small-scale studies have explored HBOT for Long COVID, with encouraging results:
* A **randomized, placebo-controlled trial of 73 patients** found that those receiving 40 sessions of hyperbaric oxygen therapy reported better sleep, attention, energy, and reduced pain. Benefits were still observed one year after treatment.
* Another study showed **improvements in heart function**, with reduced cardiac strain in patients who completed HBOT.
* A smaller trial with 10 patients found significant gains in both fatigue and cognitive performance after 10 treatments.
* Ongoing studies, including one at Sweden’s Karolinska Institute, continue to monitor safety and long-term effectiveness.
While these results are promising, researchers stress that larger, more rigorous studies are needed before HBOT can be recommended as a standard treatment.
Challenges and Barriers
Despite its potential, HBOT faces hurdles. The treatment remains **experimental for Long COVID** and is not covered by insurance. Costs are high—often **around \$60,000 for a six-week course**—making access difficult for most patients.
There are also practical questions: How many sessions are necessary for improvement? Do benefits last long-term? And which Long COVID symptoms respond best? Some patients notice changes after just 10 sessions, while others require 40 or more. Researchers also warn that Long COVID is highly variable, making it difficult to tailor treatment protocols.
Looking Ahead
Experts like Dr. Inderjit Singh of Yale and Dr. Sandra Wainwright of Greenwich Hospital agree that HBOT shows promise but should be considered an **adjunct therapy** alongside rehabilitation, exercise, and nutrition programs.
As Dr. Lisa Sanders of Yale Medicine summarizes: “We know HBOT can deliver high levels of oxygen to tissues in need. If reduced oxygen uptake is at the root of Long COVID fatigue, then perhaps this better delivery system will help at least some patients.”
For now, HBOT offers hope but not certainty. Continued research will be key to determining whether this decades-old therapy can find a new role in easing the burdens of Long COVID.
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