Vertigo after diving and flying: inner ear in focus

A 46-year-old woman returns from a week of recreational diving in the Caribbean. She made two dives a day on compressed air, the last one the morning before her flight, at about 25 meters. No dive had a rapid ascent. One hour after takeoff, she feels the room spinning, vomits twice and notices a ringing in her right ear. She cannot walk to the bathroom without support. The flight attendant asks for help, and a volunteer doctor finds the passenger pale, sweating, with her eyes trembling to one side. The scene is fictional and was written for teaching.

This text uses the picture as a setting for clinical reasoning. The trap is calling everything labyrinthitis and waiting for it to pass. Vertigo after diving has causes that change management: decompression sickness of the inner ear, which calls for a hyperbaric chamber early, inner ear barotrauma, which can even worsen with pressure, and causes that have nothing to do with diving, such as a posterior circulation stroke. The text is not a diving medicine protocol. If you play the case of the day on NEXO, you will recognize the challenge: the same complaint can point to very different places.

Key points

• Vertigo that starts after surfacing from the dive, or on the following flight, suggests decompression sickness of the inner ear until proven otherwise.
• Vertigo that starts on the descent, with difficulty equalizing, suggests inner ear barotrauma.
• The timing of onset, the type of dive and the other symptoms help separate the two.
• High-concentration oxygen and prompt contact with a hyperbaric medicine service are the first steps when decompression sickness is suspected.
• The recommended interval between the last dive and the flight is usually 24 hours.
• After decompression sickness of the inner ear, it is worth investigating a patent foramen ovale before returning to diving.

Why this is a reasoning setting

Acute vertigo is one of the complaints that most test reasoning, because the same symptom arises in the ear, the brain or the heart. After a dive, the list changes order. What would be rare in a clinic becomes likely, and what would be common must be remembered without taking the place of the most serious.

In the scenario, the clues arrive in layers. There is the history of repeated dives, the last one less than a day before the flight. There is the aircraft's ascent, which reduces the pressure around the body. And there is an intense vestibular picture with ringing on one side. Each clue pulls toward a hypothesis, and the work is to weigh them together.

What the scene teaches

The scene trains three habits. The first is to ask when the symptoms started in relation to the dive: on the descent, at depth, on the ascent or afterward. The second is to look for other signs of decompression sickness, such as joint pain, tingling, weakness or skin marks. The third is not to forget the diagnosis that has nothing to do with diving. The post on differential diagnosis with clues shows how to keep the list open without losing focus.

What is known about the inner ear in diving

The inner ear can be injured in diving by two different routes. In barotrauma, the injury comes from the pressure difference between the middle ear and the environment, almost always on the descent, when the person cannot equalize. In decompression sickness, the injury comes from inert gas bubbles that form when the pressure falls, on the ascent or after it.

A systematic review gathered reports of the two conditions and found the most useful variables for separating them (Lindfors and colleagues, 2021). Barotrauma appeared more in breath-hold diving, with air, at shallower depths and with onset on the descent. Decompression sickness appeared more in scuba diving, with gas mixtures, at greater depths and with onset on the ascent or at the surface. The same review showed that vestibular symptoms predominate in decompression sickness, and that other decompression symptoms help confirm the suspicion.

What a case series shows

An Australian series analyzed divers treated for inner ear decompression sickness at a hyperbaric service (Mason et al., 2023). Most had made repeated recreational air dives, with nothing technical. Vestibular symptoms appeared in 88 out of every 100 patients and cochlear symptoms in 38 out of every 100, according to the same study (Mason et al., 2023). Median time to the chamber was 22 hours, and complete resolution of vestibular and hearing symptoms occurred in 67 out of every 100 (Mason et al., 2023). The profile looks very much like that of the passenger in the scenario.

Pathophysiology: bubbles, pressure and the labyrinth

During a dive, the body absorbs nitrogen from the compressed air. The deeper and longer the dive, and the more consecutive dives, the greater the gas load in the tissues. On ascent, the pressure falls and the gas leaves the tissues. If it leaves too fast, bubbles form.

The flight adds another drop in pressure. The cabin is kept at most at an altitude equivalent to 2400 m, with pressure about a quarter lower than at sea level, and symptoms of decompression sickness can appear or worsen during the flight or after it (St Leger Dowse et al., 2021). That is the reason for the recommended interval before flying.

The role of patent foramen ovale

Venous bubbles are usually filtered by the lung. When there is a communication between the atria, such as patent foramen ovale, some of them can pass straight into the arterial circulation. About a quarter of adults have patent foramen ovale, but the risk of shunt-mediated disease is concentrated in those with the largest shunts (Wilmshurst, 2026). A review on type II decompression sickness describes how this path carries bubbles to the nervous system and the inner ear (Fernandez-Cisneros, 2026).

In the Australian series, patent foramen ovale was found in 6 of 10 patients investigated after the episode (Mason et al., 2023). A British series found the same proportion, 6 of 9 divers who underwent contrast echo (Stokes et al., 2025). The inner ear seems to be a preferred target of these arterial bubbles.

And barotrauma

In inner ear barotrauma, the force of pressure can rupture membranes and open a fistula between the middle and inner ear, through which the labyrinth fluid escapes. A study in divers showed changes in vestibular evoked potentials, suggesting that repeated exposure to pressure affects the balance structures even without complaints (Bozkurt et al., 2025).

How the condition presents

Inner ear decompression sickness usually begins on ascent, at the surface or in the following hours. The dominant symptom is intense vertigo, with nausea, vomiting and difficulty walking. Tinnitus and hearing loss may come along, but they are less frequent. On examination, spontaneous nystagmus is common.

Inner ear barotrauma usually begins on descent, often after a forced maneuver to equalize. The person may have ear pain, a feeling of blocked ear, blood in the canal and hearing loss. A study of patients with perilymphatic fistula confirmed by a marker in the ear fluid showed that a pop in the ear and tinnitus resembling running water were associated with the fistula (Maeda et al., 2026). The fistula sign on examination, on the other hand, was not associated with the marker in the same study.

Signs that change management

Some signs indicate more extensive decompression sickness: tingling, weakness, joint pain, purplish patches on the skin, shortness of breath or confusion. Others point to the brain: slurred speech, double vision, difficulty swallowing, loss of strength on one side or inability to sit up without support. These central signs call for thinking of stroke or arterial gas embolism.

What to ask in a few seconds

The useful questions are few. When was the last dive and at what depth? How many dives per day, and how many days in a row? Was there difficulty equalizing on descent? Did the symptoms begin in the water, at the surface or on the flight? Is there pain, tingling or weakness elsewhere? Has anything similar happened before? The post on signs, symptoms and history shows how a well-taken history can be worth more than the examination.

Differential diagnosis

The table summarizes the main guesses and the clues that help tell them apart.

Guess	Clues in favor	Clues against
Inner ear decompression sickness	Onset during ascent, at the surface or in flight; repeated scuba dives; predominant vertigo; other symptoms of decompression	Clear onset during descent with ear pain
Inner ear barotrauma	Onset during descent; difficulty equalizing; pain and blocked ear; predominant hearing loss	Onset hours after the dive without equalization effort
Perilymph fistula	Pop in the ear; tinnitus like running water; worse with exertion	No prior barotrauma
Posterior circulation stroke	Central neurological signs; nystagmus that changes direction; inability to sit without support	Normal neurological exam outside the ear
Arterial gas embolism	Brain symptoms right after surfacing; rapid ascent	Late onset and purely vestibular picture
Positional vertigo or vestibular neuritis	Postural trigger; no recent dive	Dive the day before and flight right after

The systematic review showed that the timing of onset is among the most useful clues for telling barotrauma from decompression sickness (Lindfors et al., 2021). In the scenario, nothing suggests barotrauma: the passenger had no difficulty equalizing and the symptoms began after takeoff.

The stroke that cannot be missed

Even with a history of diving, vertigo can be vascular. A patent foramen ovale also allows paradoxical embolism of thrombi, which can cause stroke (Wilmshurst, 2026). A brief neurological exam, covering speech, strength, coordination and gait, is part of the assessment. The post on arterial gas embolism and neurological decompression sickness explores this boundary further.

Barotrauma and fistula

Telling barotrauma from decompression sickness has a practical consequence. Recompression is the treatment for decompression sickness, but there is a theoretical concern that pressure could worsen a fistula. A retrospective analysis notes that chamber use in fistula is controversial, and that fistula should be in the differential of acute ear symptoms after diving (Yi et al., 2026). In the systematic review, however, most divers with barotrauma who received recompression by mistake did not get worse (Lindfors et al., 2021).

Management on board

On board, management is about support and decisions. The first step is to lay the passenger down, with her head supported, in a place where she will not fall if she has another episode. The second is to offer oxygen from the medical kit by mask, for as long as possible. Oxygen is one of the initial measures most often cited for decompression sickness, alongside hydration and recompression (Fernandez-Cisneros, 2026).

Hydration and comfort

If the passenger can drink without vomiting, oral fluids help. If vomiting prevents it, the medical kit may have material for venous access, at the discretion of the volunteer and the ground team. The text gives no antiemetic dose, because the sources read do not define one for this picture.

Diversion and decision in flight

The decision to divert is the captain's, with support from the ground medical team. The volunteer should report that decompression sickness is suspected, that the picture worsened with altitude and that definitive treatment is the hyperbaric chamber. This weighs in favor of landing where a hyperbaric medicine service exists. The post on emergencies on commercial flights and when to divert explains how this conversation usually works.

About cabin altitude

The cabin pressure drop can worsen symptoms, and in severe cases decompression sickness in flight can lead to diverting the plane to speed up recompression (St Leger Dowse et al., 2021). In the Australian series, those flown to the chamber traveled in a medical transport aircraft with the cabin pressurized to sea level, with oxygen by mask and intravenous fluids (Mason et al., 2023). The post on hypobaric hypoxia in flight explains the physics of the pressurized cabin.

On the ground: hyperbaric chamber

The standard treatment for decompression sickness is pure oxygen at 2.82 atmospheres absolute, the US Navy table 6 (Fernandez-Cisneros, 2026). The sooner, the better. That is why the choice of destination airport, when a diversion is needed, should consider the distance to a chamber, and not only the size of the hospital. In an analysis of patients with hearing loss after diving, early chamber treatment was associated with better hearing recovery, while vestibular symptoms responded less (Yi and colleagues, 2026).

A chamber for barotrauma too?

In barotrauma, the chamber is not the classic treatment. One series described divers with sensorineural hearing loss from inner ear barotrauma who improved with hyperbaric oxygen, all without signs of fistula and able to equalize their ears (Smart, 2024). Careful selection is the central point. Before indicating the chamber in barotrauma, the diving physician looks for signs of fistula and confirms that the middle ear equalizes, because these conditions change the balance between benefit and risk.

The hearing exam

The tuning fork allows a quick bedside test to tell whether the hearing loss is conductive, as in a middle ear full of blood, or sensorineural, as in inner ear injury. In the service, audiometry and vestibular tests document the size of the injury. The post on pretest probability helps to think about how much each test changes the hypothesis.

Recovery, rehabilitation and return to diving

Even with treatment, some divers are left with sequelae. A British series followed divers with inner ear decompression sickness in vestibular rehabilitation. Balance and quality of life measures improved, but 67 out of 100 still had signs of vestibular deficit on tests three months later (Stokes and colleagues, 2025). The authors suggest starting rehabilitation exercises early and using a sensitized, timed Romberg test to track improvement.

Investigating the shunt

The joint statement from the diving medicine societies of Australia and the United Kingdom recommends considering investigation of a right-to-left shunt after vestibulocochlear decompression sickness (Smart and colleagues, 2025). The same statement says routine screening in the fitness-to-dive examination is not indicated. The recommended test is contrast echocardiography with agitated saline, performed by centers with practice in the technique (Wilmshurst, 2026).

Diving again

If a relevant shunt is found, the diver discusses the options with a diving physician, which include stopping, diving more conservatively or closing the shunt. The joint statement advises not returning to diving before confirming closure (Smart and colleagues, 2025). The post on prognostic reasoning discusses how to think about what comes after the diagnosis.

Prevention: the interval before flying

The most common recommendation for recreational divers is to wait 24 hours between the last dive and the flight, with other guidelines ranging from 18 to 48 hours (St Leger Dowse and colleagues, 2021). In a questionnaire with divers on vacation, 79 out of 100 reported having waited at least 24 hours (St Leger Dowse and colleagues, 2021). The authors note that, for a small group more prone to forming bubbles, even that interval may not be enough.

In the scenario, the passenger flew less than a day after her last dive, after a week with two dives a day. The accumulated gas load and the short interval add up to risk. The post on fitness to fly covers the questions worth asking before boarding.

What to advise the diver

Schedule the last dive for at least a day before the flight. Avoid repeated and deep dives in the final days of the trip. Drink fluids and avoid intense exertion after diving. And seek help early when feeling vertigo, tingling or pain after diving, without waiting for the symptom to go away.

Step-by-step reasoning in the case

First, the context clue: a week of repeated air dives, the last less than a day before the flight. The gas load is high and the interval is short.

Second, the timing clue: the vertigo began after takeoff, and not during the dive descent. This rules out barotrauma and brings decompression sickness closer.

Third, the clue from the chart: intense vertigo, vomiting, nystagmus and tinnitus on one side. It is the picture of decompression sickness of the inner ear, with vestibular predominance.

Fourth, the search for other signs: the volunteer asks about pain, tingling and weakness, and does a brief neurological exam. If there are central signs, stroke and gas embolism move up the list.

Fifth, the management: the passenger lies down, receives oxygen and fluids if tolerated. The volunteer informs the captain about the suspicion.

Sixth, the decision: the definitive treatment is the hyperbaric chamber, and time matters. The ground team helps choose the destination.

Seventh, the aftermath: early vestibular rehabilitation and investigation of a shunt before returning to diving.

Common mistakes

The first mistake is calling it labyrinthitis and waiting. After a dive, vertigo calls for thinking of decompression sickness.

The second mistake is not asking when the symptoms started. The timing is one of the most useful clues for separating the hypotheses.

The third mistake is treating every tinnitus as barotrauma. Tinnitus also appears in decompression sickness.

The fourth mistake is forgetting stroke. A patent foramen ovale allows both bubbles and thrombi.

The fifth mistake is waiting for landing to think about the chamber. The conversation with the ground team can start in the air.

The sixth mistake is clearing the diver to return to the water without investigating a shunt. Recurrence is a known risk.

The seventh mistake is thinking that improvement of symptoms means full recovery. Vestibular tests may remain abnormal. The post about diagnostic pause reminds you to stop before closing the case.

How NEXO helps train this reasoning

To use the case of the day as training, try three habits. Before the first guess, ask which serious diagnosis calls for immediate action. With each clue, ask when the symptom started and what that changes. After the result, note which hypothesis you ruled out too early.

Three exercises with cases

Put it on the timeline. For each case of vertigo, mark the onset in relation to the trigger and see whether the hypothesis changes.

Look for the central sign. List the findings that point to the brain and check whether you looked for them.

Think about the aftermath. Write down what the person needs to know before returning to the activity that caused the problem.

The post about diagnostic uncertainty brings strategies for deciding without all the data, and the post about learning based on clinical cases shows how cases help fix this habit.

The limits on using the game are described on the NEXO economy page. If you research the teaching of clinical reasoning, the page for researchers explains how to get in touch. Professionals who write or review cases find information on curation and on creators, and institutions can learn about the proposal on the partnerships page.

Frequently asked questions

Can vertigo after diving be decompression sickness?

Yes. Vertigo that starts on ascent, at the surface or on the following flight suggests decompression sickness of the inner ear (Lindfors et al., 2021).

Does flying soon after diving increase the risk?

Yes. The most common recommendation is to wait 24 hours between the last dive and the flight (St Leger Dowse et al., 2021).

Is the hyperbaric chamber the treatment for decompression sickness?

Yes. The standard treatment is oxygen under pressure in a hyperbaric chamber (Fernandez-Cisneros, 2026).

Is it worth investigating a patent foramen ovale after the episode?

Yes. The joint statement recommends considering the investigation after vestibulocochlear decompression sickness (Smart et al., 2025).

Does vestibular rehabilitation help recovery?

Yes. The authors of a British series suggest starting the exercises early (Stokes et al., 2025).

Final checklist

• I asked when the last dive was, the depth and how many dives in a row.
• I established when the symptoms started: descent, ascent, surface or flight.
• I asked about difficulty equalizing and ear pain.
• I looked for other signs of decompression sickness.
• I did a brief neurological exam so as not to miss a stroke.
• I laid the passenger down and offered oxygen.
• I informed the captain about the suspicion and the need for a chamber.
• I advised vestibular rehabilitation and investigation of a shunt.
• I reminded her of the interval before flying in the final guidance.

Want to practice your reasoning with progressive clues? Play today's case.

References

1. Bozkurt Ö, Güven SG, Taş M, et al. Evaluation of the Peripheral Vestibular System due to Inner Ear Barotrauma in the Hyperbaric Environment. Laryngoscope Investig Otolaryngol. 2025. PMID 40843147.
2. Fernandez-Cisneros A. Decompression sickness type II and patent foramen ovale: when a common congenital anomaly becomes a life-threatening risk. Med Gas Res. 2026. PMID 40826946.
3. Lindfors OH, Räisänen-Sokolowski AK, Hirvonen TP, et al. Inner ear barotrauma and inner ear decompression sickness: a systematic review on differential diagnostics. Diving Hyperb Med. 2021. PMID 34897597.
4. Maeda Y, Matsuda H, Kitahara T, et al. Popping sound and streaming water-like tinnitus in Cochlin-tomoprotein-confirmed perilymphatic fistula with antecedent barotrauma. Front Neurol. 2026. PMID 42723732.
5. Mason JS, Buzzacott P, Gawthrope IC, et al. A retrospective review of divers treated for inner ear decompression sickness at Fiona Stanley Hospital hyperbaric medicine unit 2014-2020. Diving Hyperb Med. 2023. PMID 37718299.
6. Smart D. Five consecutive cases of sensorineural hearing loss associated with inner ear barotrauma due to diving, successfully treated with hyperbaric oxygen. Diving Hyperb Med. 2024. PMID 39675746.
7. Smart D, Wilmshurst P, Banham N, et al. Joint position statement on atrial shunts (persistent [patent] foramen ovale and atrial septal defects) and diving: 2025 update. South Pacific Underwater Medicine Society (SPUMS) and the United Kingdom Diving Medical Committee (UKDMC). Diving Hyperb Med. 2025. PMID 40090026.
8. St Leger Dowse M, Howell S, Smerdon GR. Flying after diving: a questionnaire-based evaluation of pre-flight diving behaviour in a recreational diving cohort. Diving Hyperb Med. 2021. PMID 34897601.
9. Stokes RJ, Watts D, Smerdon G, et al. Vestibular rehabilitation and recovery in divers with inner ear decompression sickness: a case series. Diving Hyperb Med. 2025. PMID 40986919.
10. Wilmshurst P. Persistent (patent) foramen ovale assessment and closure for the general physician. Clin Med (Lond). 2026. PMID 42176897.
11. Yi TC, Weng TH, Chen HC. Characteristics and Prognostic Analysis in Diving-Induced Ear Trauma and Sudden Hearing Loss. J Clin Med. 2026. PMID 42194831.