Diabetes and Hyperbaric Oxygen Therapy: Why We Check Your Blood Sugar Before Every Session
Lisa St. John, M.S.
Lisa is our Clinic Director and Founder. She earned her Master's degree from Harvard University, completed a Fellowship at Stanford University, and has spent the last 30 years working in the healthcare field.
If you have diabetes, hyperbaric oxygen therapy (HBOT) can be a safe and effective option, especially for foot wounds that won't heal. Because HBOT can lower blood sugar in some people, your care team checks your glucose before (and often after) each session. Eating normally, taking your medications as directed and telling us how you feel are the best ways to stay safe.
"Why Are You Poking My Finger Again?"
If you're a regular at the clinic, you may have noticed the first thing we do is check your blood sugar. It can feel repetitive, especially if you manage your diabetes carefully at home.
There's a good reason. Research suggests oxygen under pressure can nudge blood sugar down in some patients, and the risk is highest for people who take insulin or certain diabetes medications. A quick check before treatment helps us catch a problem early, before you're sealed inside a chamber for an hour or more.
Why HBOT Matters for People With Diabetes
Diabetes can damage small blood vessels and nerves, which reduces oxygen delivery to the feet and slows healing. A small sore can turn into a stubborn wound, and wounds like these are a leading reason people with diabetes face serious infection or amputation.
HBOT floods the blood with extra oxygen, helping damaged tissue fight infection and grow new blood vessels. For chronic diabetic foot ulcers, a Cochrane review found HBOT improved the chance of healing in the short term when added to standard wound care. Medicare covers HBOT for diabetic wounds of the lower leg that meet its criteria, which include a Wagner grade III or higher ulcer that hasn't improved after a trial of standard care (CMS NCD 20.29). Your physician will confirm whether you qualify.
How Blood Sugar Fits Into Your Session
Here's what to expect:
Before your session: We check your glucose. If it's in your target range, you go ahead. If it's too low, we'll have you eat or drink something and recheck first. If it's too high, your physician may adjust the plan.
During your session: You can talk to the team on the intercom the whole time. If you feel shaky, sweaty, lightheaded or unusually hungry, tell us right away. Those can be signs of low blood sugar.
After your session: We may check again before you head home, especially if you take insulin.
Tips to Stay Comfortable and Safe
Don't skip meals. Eat as you normally would before treatment. Going in hungry raises the risk of a low.
Take your medications as directed. Don't change doses on your own. Ask your physician if your regimen needs adjusting during HBOT.
Bring your supplies. Bring your meter, and let us know if you carry glucose tablets or snacks.
Ask about devices. Insulin pumps and many continuous glucose monitors (CGMs) generally can't go inside the chamber, so we'll plan ahead with you. This is the same fire-safety rule that applies to phones and other electronics.
Tell us how you feel. You'll never be bothering us.
Safety and Expert Care
At Bay Area Hyperbarics, safety is built into every session. Our team reviews your medical history, checks your glucose, and works with your primary care provider, endocrinologist or wound care team so everyone is on the same page.
Consult a healthcare provider before starting any new treatment. This article is for educational purposes and does not replace medical advice from your care team.
Frequently Asked Questions
Does HBOT lower blood sugar? It can in some patients, particularly those who take insulin or certain oral medications. That's why we check your glucose before treatment.
Should I eat before an HBOT session if I have diabetes? Yes. Eat normally unless your physician tells you otherwise. Going in on an empty stomach increases the risk of a low.
Can I wear my insulin pump or CGM in the chamber? Typically not. We'll review your devices with you before your first session and plan around them.
Is HBOT covered for diabetic foot ulcers? Medicare and many private insurers cover HBOT for qualifying diabetic wounds of the lower leg. Our team can help you check your coverage.
What if my blood sugar is too high or too low on the day? We'll treat a low first and recheck, and your physician will decide how to proceed if it's high. You won't be sent in until it's safe.
Living with diabetes and a wound that won't heal? Call our team to learn whether HBOT could help.
