HBOT is generally not painful. The most common sensation experienced is pressure in the ears during the pressurization phase, similar to what you feel on an airplane [Sensations During Hyperbaric Oxygen Therapy](https://www.plasticitycenters.com/blog/how-hyperbaric-oxygen-therapy-feels-during-sessions). Your medical team will guide you on how to equalize this pressure to ensure comfort. For first-timers, gentle pressure is often used to allow for adjustment [Understanding Your First HBOT Dive](h

The Complete Beginner's Guide to Hyperbaric Oxygen Therapy

Last updated: April 2026

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Consult a qualified healthcare provider before starting any treatment.

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Quick Answer

Before your first hyperbaric oxygen therapy (HBOT) treatment, eat a snack or meal within an hour of your appointment to provide your body with protein and raise your blood sugar for healing Preparing for Your First Hyperbaric Treatment.
During a "dive," you breathe 100% medical-grade oxygen while the chamber pressure is increased above normal atmospheric pressure Understanding Your First HBOT Dive.
Your intake session typically takes place right before your first hyperbaric treatment and lasts 30-45 minutes Preparing for Your First Hyperbaric Treatment.
A hyperbaric dive refers to the gradual increase of pressure inside the chamber, which is similar to the sensation of descending underwater Understanding Your First HBOT Dive.

Hyperbaric oxygen therapy (HBOT) is a specialized medical treatment where you breathe pure oxygen inside a pressurized chamber. This process allows your body to take in much more oxygen than it normally could under regular air pressure Sensations During Hyperbaric Oxygen Therapy. This increased oxygen helps your body heal, reduce swelling, and repair cells throughout your system. For example, the intake process before your first session often takes 30-45 minutes to ensure you are fully prepared and comfortable Preparing for Your First Hyperbaric Treatment. Understanding what happens during your first session can help you feel more at ease and decide if HBOT is right for your health or recovery goals.

What is Hyperbaric Oxygen Therapy (HBOT)?

Hyperbaric oxygen therapy (HBOT) is a medical treatment that involves breathing pure oxygen in a special room, called a hyperbaric chamber, where the air pressure is much higher than normal. This increased pressure allows your body to absorb a significantly greater amount of oxygen than it would typically from the air we breathe every day. The extra oxygen then travels through your bloodstream, reaching areas of your body that might be injured or have poor blood flow, helping them to heal. This environment supports critical body functions, including brain repair, reducing inflammation, and promoting the recovery of cells throughout your body Sensations During Hyperbaric Oxygen Therapy.

How HBOT Works in Your Body

Under normal conditions, oxygen binds to hemoglobin in your red blood cells. However, hemoglobin quickly becomes fully saturated. When you undergo HBOT, the increased pressure in the chamber allows oxygen to dissolve directly into your blood plasma, not just bind to hemoglobin Understanding Your First HBOT Dive. This means your blood can carry much more oxygen than usual. This extra oxygen can reach tissues that typically receive very little blood flow, such as tendons, cartilage, and injured tissue. This direct delivery to plasma is key to how HBOT can help speed up recovery from various conditions. The process essentially supercharges your body's natural healing mechanisms by making more oxygen available at a cellular level.

Benefits of Increased Oxygen

The surge of oxygen delivered during HBOT sessions has several important benefits. It helps to reduce swelling, fight off certain infections, and stimulate the growth of new blood vessels. For example, this therapy is used to assist patients in faster recovery for everything from cosmetic surgery to sports injuries Understanding Your First HBOT Dive. The increased oxygen also supports the body's ability to repair damaged tissues and can enhance overall wellness. It can improve cognitive function by providing more oxygen to the brain, which is vital for neurological recovery. Many patients report improved energy levels and a general sense of well-being after a series of treatments. The fundamental principle is that oxygen is essential for nearly all cellular functions, and by maximizing its delivery, we can optimize the body's repair processes.

Conditions HBOT Can Support

While HBOT is recognized for its potential in various areas, it is important to understand that it is a specialized medical treatment. The therapy is used for conditions where increasing oxygen delivery to tissues is beneficial. This can include supporting neurological recovery, improving cognitive function, and enhancing overall wellness Sensations During Hyperbaric Oxygen Therapy. For instance, it helps in the healing of chronic wounds that have not responded to other treatments, and it can be part of a recovery plan for certain types of injuries or post-surgical healing. The specific conditions that can benefit from HBOT are determined by medical professionals, who consider individual patient needs and the scientific evidence supporting its use. The goal is always to deliver oxygen to areas that are struggling to heal due to lack of adequate oxygen, thereby boosting the body's natural regenerative capabilities.

How Do I Prepare for My First HBOT Session?

Preparing for your first hyperbaric oxygen therapy (HBOT) session involves a few key steps designed to ensure your safety and maximize the effectiveness of your treatment. These steps begin even before you arrive at the clinic, starting with initial discussions and continuing right up to your appointment time. We want to make sure you feel ready and informed for your first "dive."

Initial Consultations and Medical History

Before your first treatment, you will likely spend a few minutes speaking with a medical professional, such as a nurse or a senior hyperbaric technician. For example, Laura Jean RN, a nurse, or David Roberts, a Senior Hyperbaric Technician, will ask you questions about your medical history Preparing for Your First Hyperbaric Treatment. This conversation is crucial for determining if HBOT is a good option for you. They will take the time to answer any questions you have, explain how hyperbarics works, and address any difficulties or concerns you might be feeling. They will then help you set up your appointment for both the intake and your first hyperbaric treatment. This initial contact is designed to build trust and ensure all your preliminary questions are answered.

The Importance of Eating Before Treatment

One important instruction for preparing for your first hyperbaric treatment is to eat a snack or meal within an hour or so before you come in Preparing for Your First Hyperbaric Treatment. This is not a casual suggestion; it is a critical step. Eating provides your body with plenty of protein, which is especially important when you are healing from injuries. It also helps to raise your blood sugar high enough for your treatment. Hyperbaric oxygen therapy uses a significant amount of the fuel available in your bloodstream to help you heal while you are in the chamber. Without enough fuel, your body may not be able to utilize the increased oxygen as effectively. Therefore, a good meal or snack ensures your body has the energy reserves needed to make the most of the therapy.

What to Bring to Your Appointment

As you get ready for your intake and first hyperbaric session, remember to bring essential documents. These typically include your identification and any insurance cards if they apply to your treatment. Additionally, bring any paperwork from your prescribing physician Preparing for Your First Hyperbaric Treatment. Having all these documents ready will help streamline the intake process and ensure that your medical team has all the necessary information to provide the best care. It also helps in verifying your treatment plan and ensuring that everything aligns with your doctor's recommendations. Organizing these items beforehand can reduce stress on the day of your appointment.

Arriving for Your Intake

It is recommended that you arrive 30-45 minutes before your first hyperbaric treatment session for your intake Preparing for Your First Hyperbaric Treatment. This specific timing is set up to ensure you have plenty of time and are not rushed through your scheduled intake. This allows for a relaxed discussion, completion of any final paperwork, and an opportunity to ask any last-minute questions you might have. We want you to feel calm and ready, not hurried, as you begin your healing journey. This buffer time is part of creating a comfortable and supportive environment for all our patients, ensuring a smooth transition into your treatment.

What Happens During Your First HBOT Treatment?

Your first hyperbaric oxygen therapy (HBOT) treatment is designed to be a comfortable and informative experience. From the moment you arrive until you leave, the focus is on your care, respect, and ensuring you have a relaxing time as you begin to heal. We understand that some patients may feel a bit nervous before their first treatment, which is completely normal, but there is nothing to worry about.

Your Arrival and Welcome

When you arrive for your first visit, you will find a welcoming atmosphere. Clinics are often designed to be inviting, moving away from the typical cold, sterile medical environment Preparing for Your First Hyperbaric Treatment. We believe that your environment is important to your healing process, just as much as our staff and your treatment itself. Our friendly staff will greet you and may offer you coffee, tea, water, or a snack. We invite you into a private room for a discussion and to enjoy a comfortable, relaxed atmosphere. You are also welcome to bring a family member or friend with you; we would be happy to meet them too. This initial welcome is crucial for setting a positive tone for your entire treatment experience.

The Intake Process

Your intake typically takes place right before your first hyperbaric treatment. This session is often conducted by experienced professionals, such as David Roberts, a Senior Hyperbaric Technician with 20 years of experience, or Laura Jean, an RN Preparing for Your First Hyperbaric Treatment. This is a dedicated time to review what you expect from the treatment and how hyperbaric oxygen will heal your specific condition. "This is the time we take to review with you what you are expecting, your treatment and how hyperbaric oxygen heals your specific condition. We will tell you all about your upcoming treatments and answer any further questions you might have," said David Roberts, Senior Hyperbaric Technician. We will also go over your medical history again and review paperwork to ensure you understand your payment and insurance coverage, as well as how HBOT will help your body heal and often get you back to doing the things and spending time with the people you love.

Preparing for the Chamber

Before entering the hyperbaric chamber, you will receive specific instructions to ensure your safety and comfort. You may be asked to change into cotton clothing approved for the chamber. It is also important to remove certain items, such as watches, skincare products, and electronics Understanding Your First HBOT Dive. These precautions are in place to prevent any potential risks associated with the high-oxygen, high-pressure environment inside the chamber. A provider will review all safety protocols with you and confirm the pressure and oxygen settings that are tailored specifically for your needs. This preparation helps ensure a safe and effective treatment session.

Orientation to Your Chamber and Safety Protocols

Before your "dive," you will receive an orientation to the hyperbaric chamber itself. This includes understanding how to communicate with the staff during your session and what to expect regarding the environment inside. The medical team will review all safety protocols in detail. For example, they will explain why certain items are not allowed in the chamber and what to do if you feel uncomfortable. This thorough review of safety measures is paramount, ensuring that you are fully aware of the process and can relax knowing that your well-being is the top priority. Understanding these protocols helps to ease any apprehension and builds confidence in the treatment process.

What Does a “Hyperbaric Dive” Mean?

In the context of hyperbaric oxygen therapy (HBOT), the word "dive" is often used to describe a session inside the chamber. While it might sound intimidating, a hyperbaric dive has nothing to do with water. Instead, it refers to the process of gradually increasing pressure inside the chamber, which is similar to the pressure changes experienced when descending underwater as a diver Understanding Your First HBOT Dive. This term helps to explain the feeling of pressure you might experience, much like the balance underwater divers use to match the pressure of the water with the pressure inside their wetsuits.

The Dual Changes Inside the Chamber

During a hyperbaric dive, two main things happen simultaneously inside the chamber. First, you breathe 100% medical-grade oxygen Understanding Your First HBOT Dive. This is a much higher concentration of oxygen than the approximately 21% found in normal air. Second, the pressure inside the chamber is increased to levels above normal atmospheric pressure. This combination is crucial for the therapy's effectiveness. The pure oxygen, combined with the elevated pressure, creates an environment where your body can absorb and utilize oxygen far more efficiently than under normal conditions. This dual action is what makes HBOT unique and powerful for healing.

How Pressure Enhances Oxygen Delivery

The increased pressure is what truly sets HBOT apart. Under normal atmospheric conditions, oxygen primarily binds to hemoglobin in your red blood cells. However, hemoglobin quickly becomes fully saturated. The elevated pressure inside the hyperbaric chamber allows oxygen to dissolve directly into your blood plasma, independent of hemoglobin Understanding Your First HBOT Dive. This means that oxygen levels in your blood can rise far beyond their usual limits. This dissolved oxygen can then reach tissues that typically receive very little blood flow, such as tendons, cartilage, and injured areas, where it can promote healing and reduce inflammation. This mechanism is why HBOT is so effective in treating conditions where tissue oxygenation is compromised.

The "Descent" Phase: Pressurization

The pressurization phase of an HBOT session is often called the "descent" because the sensation is similar to descending in an airplane or underwater. During this time, the pressure inside the chamber gradually increases. For your first session, the medical team will often start with gentle pressure, allowing you and your body to adjust to this new sensation Understanding Your First HBOT Dive. This gradual increase helps to minimize discomfort and allows you to equalize the pressure in your ears, much like you would during a flight. The staff will provide guidance on how to clear your ears, such as by swallowing or yawning, to ensure your comfort throughout this phase.

Staying Comfortable During the Dive

Once the chamber reaches its target pressure, you will remain there for the prescribed treatment time. During this period, you will continue to breathe 100% medical-grade oxygen. The chamber environment is usually controlled for temperature and humidity to ensure your comfort. Many patients use this time to relax, read, listen to music, or even sleep. The primary goal is to allow the increased oxygen to circulate throughout your body and initiate its healing effects. The staff monitors you throughout the session and is available to communicate if you have any questions or concerns. This phase is typically calm and uneventful, allowing your body to focus entirely on absorbing the therapeutic oxygen.

What Does HBOT Feel Like?

Understanding the physical sensations and mental experiences during a hyperbaric oxygen therapy (HBOT) session can help ease any concerns and set realistic expectations. While the science behind HBOT is widely known, fewer people understand what a session actually feels like Sensations During Hyperbaric Oxygen Therapy. It is not painful, but there are distinct sensations associated with the change in pressure.

Initial Sensations: Entering the Chamber

When you first enter the hyperbaric chamber, it might feel a bit like a small, enclosed room. Depending on the type of chamber, it could be a monoplace chamber, designed for one person, or a multiplace chamber, which can accommodate several patients along with a medical attendant. You will sit or lie down comfortably. Before the "dive" begins, the chamber will be at normal atmospheric pressure, so there will be no unusual sensations at this point. The staff will ensure you are settled and understand the communication system, typically an intercom, so you can speak with them at any time. This initial stage is all about getting comfortable and ready for the pressurization phase.

The Pressurization Phase: Pressure in the Ears

The most noticeable sensation during an HBOT session occurs during the pressurization, or "descent," phase. The primary sensation during this time is pressure in your ears Sensations During Hyperbaric Oxygen Therapy. This feeling is very similar to what you might experience when flying in an airplane, driving up or down a mountain, or diving underwater. It happens because the increasing pressure outside your eardrum needs to be equalized with the pressure inside your middle ear. To manage this, you will be taught techniques to "clear" your ears, such as swallowing, yawning, or performing the Valsalva maneuver (gently blowing your nose while holding it closed). The medical team often starts with gentle pressure, especially for first-timers, allowing your body to adjust gradually Understanding Your First HBOT Dive. This ensures that you can equalize the pressure comfortably.

Other Physical Sensations

Besides the ear pressure, you might notice a slight warmth inside the chamber as the pressure increases Sensations During Hyperbaric Oxygen Therapy. This is a normal effect of gas compression and is usually mild and temporary. Some patients also report a feeling of fullness in their sinuses or a slight crackling sensation in their ears. These are all normal physiological responses to the change in pressure. The chamber environment is typically controlled for temperature and humidity to maintain a comfortable experience. "They discuss our process and whether hyperbarics is a good option for you. They also talk about how hyperbarics works, and help address any difficulties or concerns you might have," said Laura Jean RN, a nurse. This comprehensive discussion ensures patients are prepared for all sensations.

During the Treatment Period: Relaxation and Calm

Once the target pressure is reached and your ears are equalized, the sensations usually subside, and the rest of the session is generally calm and quiet. You will simply relax and breathe the pure oxygen. Many patients find this time peaceful and use it for quiet reflection, reading a book, watching a movie (if available in multiplace chambers), or even taking a nap. The increased oxygen is working silently within your body, promoting healing and recovery. The staff will continuously monitor you through observation windows and intercoms, ensuring your safety and comfort throughout the entire treatment duration. This period is often described as surprisingly relaxing, allowing patients to unwind while their bodies receive therapeutic benefits.

The Depressurization Phase: The "Ascent"

At the end of your session, the pressure inside the chamber will be slowly decreased back to normal atmospheric levels. This phase is known as the "ascent." During this time, you might feel a popping or clicking sensation in your ears as the pressure equalizes in the opposite direction. This is usually less noticeable and easier to manage than the pressurization phase. The medical team will guide you through this process. Once the pressure is fully normalized, the chamber door will be opened, and you can exit, often feeling refreshed and relaxed. The entire experience is carefully managed to ensure your comfort and safety from start to finish.

What Are the Potential Risks of Hyperbaric Oxygen Therapy?

Understanding the potential risks of any medical procedure, including hyperbaric oxygen therapy (HBOT), is an important part of making informed decisions about your health. While HBOT is generally considered safe when administered by trained professionals in a controlled environment, it is not without potential side effects or complications. Discussing any concerns with your provider before starting treatment is crucial to ensure it aligns with your health profile and needs.

Common Side Effects and How to Manage Them

The most common side side effects of HBOT are usually related to the pressure changes during the "dive" and "ascent" phases. As mentioned, the primary sensation is pressure in the ears, similar to flying. If you have trouble equalizing the pressure, it can lead to ear discomfort or, in rare cases, ear barotrauma, which is damage to the eardrum. However, staff provide guidance on ear equalization techniques to help prevent this. For example, patients are coached on how to swallow, yawn, or perform the Valsalva maneuver to clear their ears Sensations During Hyperbaric Oxygen Therapy. Other minor side effects can include temporary vision changes, such as mild nearsightedness, which typically resolves after treatment. Some patients might also experience fatigue after a session, as the body uses a lot of energy for healing.

Risks Associated with Oxygen Toxicity

While breathing 100% medical-grade oxygen is central to HBOT, too much oxygen at high pressures can lead to oxygen toxicity. This is a rare but serious risk. Symptoms of oxygen toxicity can include visual changes, ringing in the ears, nausea, muscle twitching, irritability, and in very rare cases, seizures. However, the risk of oxygen toxicity is carefully managed by medical professionals who closely monitor the pressure levels and treatment durations. For instance, treatment protocols are designed to keep oxygen exposure within safe limits, and breaks from oxygen are sometimes incorporated into longer sessions. A provider will review safety protocols and confirm pressure and oxygen settings tailored to you Understanding Your First HBOT Dive. This careful tailoring helps prevent oxygen toxicity.

Other Potential Complications

Other potential, though less common, risks of HBOT include sinus squeeze, which is discomfort or pain in the sinuses due to pressure changes, and claustrophobia for some individuals in enclosed chambers. In very rare instances, there could be a risk of fire due to the high oxygen environment, but clinics take extensive precautions, such as requiring patients to remove electronics and wear cotton clothing, to mitigate this risk Understanding Your First HBOT Dive. Pneumothorax, or a collapsed lung, is another extremely rare complication, particularly for patients with pre-existing lung conditions. This is why a thorough medical history review is conducted before treatment. "They discuss our process and whether hyperbarics is a good option for you. They also talk about how hyperbarics works, and help address any difficulties or concerns you might have," said Laura Jean RN, a nurse, emphasizing the importance of screening.

Contraindications and Patient Screening

Because of these potential risks, thorough patient screening is a critical step before starting HBOT. Certain conditions are considered contraindications, meaning they would make HBOT unsafe. These can include untreated pneumothorax (collapsed lung) and certain types of medications. During your initial consultation, a nurse or senior hyperbaric technician will ask you questions about your medical history to identify any potential risks Preparing for Your First Hyperbaric Treatment. It is essential to be completely honest and comprehensive about your health history, medications, and any pre-existing conditions. This careful evaluation ensures that HBOT is a safe and appropriate treatment option for you, minimizing potential risks and maximizing therapeutic benefits.

How is HBOT Different from Regular Oxygen Therapy?

Hyperbaric oxygen therapy (HBOT) is fundamentally different from regular oxygen therapy, even though both involve delivering oxygen to a patient. The key distinction lies in the environment where the oxygen is delivered, specifically the increased atmospheric pressure that is central to HBOT. This difference in pressure dramatically changes how oxygen behaves in the body and its therapeutic potential.

The Role of Pressure in HBOT

In regular oxygen therapy, patients typically breathe supplemental oxygen through a mask or nasal cannula at normal atmospheric pressure. While this increases the amount of oxygen available in the lungs, the amount of oxygen that dissolves into the blood plasma is limited. HBOT, on the other hand, involves breathing 100% medical-grade oxygen while the chamber pressure is increased above normal atmospheric pressure Understanding Your First HBOT Dive. This elevated pressure is the game-changer. It allows oxygen to dissolve directly into the blood plasma, rather than just binding to hemoglobin in red blood cells. Under normal conditions, hemoglobin becomes fully saturated quickly, limiting further oxygen uptake. Pressure is what allows oxygen levels in the blood to rise beyond that limit, significantly increasing the body's oxygen-carrying capacity.

Deeper Penetration to Tissues

Because HBOT allows oxygen to dissolve directly into the plasma, this increased oxygen can reach tissues that typically receive very little blood flow. These include areas like tendons, cartilage, and injured tissues that may be struggling to heal due to poor circulation Understanding Your First HBOT Dive. In contrast, regular oxygen therapy primarily boosts oxygen levels in areas with good blood supply but does not have the same ability to force oxygen into poorly perfused or damaged tissues. This deeper penetration of oxygen into compromised areas is why HBOT is particularly effective for conditions involving tissue damage, chronic wounds, or low oxygen states. The mechanism essentially bypasses the limitations of the circulatory system in delivering oxygen to every cell.

Therapeutic Effects and Applications

The enhanced oxygen delivery in HBOT leads to distinct therapeutic effects that are not achievable with regular oxygen therapy. The increased oxygen availability can support brain repair, reduce inflammation, and promote cellular recovery Sensations During Hyperbaric Oxygen Therapy. This makes HBOT a valuable treatment for a wider range of complex medical conditions, including certain types of infections, non-healing wounds, radiation injury, and neurological conditions. For example, at Clinic 5C Functional Medicine, HBOT is used to assist patients in faster recovery in everything from cosmetic surgery to sports injuries Understanding Your First HBOT Dive. Regular oxygen therapy, while beneficial for respiratory issues or acute oxygen deprivation, does not offer the same level of tissue oxygenation or the same broad spectrum of healing benefits. The fundamental difference lies in the physiological impact of pressure-enhanced oxygen saturation.

Frequently Asked Questions

How long does a typical HBOT session last?

A typical hyperbaric oxygen therapy session can vary in length, but generally, it lasts between 60 to 90 minutes once the target pressure is reached. This does not include the initial pressurization and final depressurization phases. For your first visit, you should plan to arrive 30-45 minutes early for your intake, making the total visit longer than just the time in the chamber Preparing for Your First Hyperbaric Treatment.

Can I bring personal items into the chamber?

During your first HBOT session, you will typically be asked to change into cotton clothing approved for the chamber. You must also remove personal items such as watches, skincare products, and electronics Understanding Your First HBOT Dive. These precautions are put in place to ensure your safety and prevent any potential risks in the high-oxygen environment.

Is HBOT painful?

HBOT is generally not painful. The most common sensation experienced is pressure in the ears during the pressurization phase, similar to what you feel on an airplane Sensations During Hyperbaric Oxygen Therapy. Your medical team will guide you on how to equalize this pressure to ensure comfort. For first-timers, gentle pressure is often used to allow for adjustment Understanding Your First HBOT Dive.

How many HBOT sessions are usually needed?

The number of HBOT sessions needed varies greatly depending on the specific condition being treated, the severity of the condition, and individual patient response. Some conditions may require a few sessions, while others, particularly chronic issues or complex wound healing, might need 20 or more treatments. Your medical provider will develop a personalized treatment plan based on your needs and how hyperbaric oxygen heals your specific condition Preparing for Your First Hyperbaric Treatment.

Who performs the HBOT treatment?

HBOT treatments are performed by trained medical professionals. This can include nurses (like Laura Jean RN) or senior hyperbaric technicians (like David Roberts, who has 20 years of experience) Preparing for Your First Hyperbaric Treatment. These specialists are responsible for overseeing your safety, monitoring the chamber, and ensuring that all protocols are followed. They will also be available to answer any questions and address concerns you might have during your sessions.