Flying with a chest infection
A chest infection reduces your available lung function at exactly the moment the cabin gives you less oxygen to work with.
The short answer. Better to wait until it has settled. There is no airline rule banning it, but a chest infection reduces the lung capacity you have available just as the cabin reduces the oxygen on offer. The CAA’s practical test is whether you can walk 50 metres or climb a flight of stairs without significant breathlessness.
Two problems at once
At cruising altitude the cabin gives you noticeably less oxygen than sea level. Healthy lungs absorb it without difficulty. Lungs that are inflamed, congested and partly filled with infection do not, and the result can be breathlessness that you would not have on the ground.
The second problem is more mundane but more common: sinus and middle ear congestion. A chest infection usually comes with upper airway congestion, which stops the ears equalising and makes descent genuinely painful. More on that.
The CAA’s practical test
The CAA offers a usefully simple assessment that you can do at home: If a passenger can walk 50 yards or metres at a normal pace, or climb one flight of stairs without significant breathlessness, supplemental oxygen should not usually be required. If you cannot manage that comfortably at the moment, you are not in good shape for a flight.
And the obvious point
If you are coughing and feverish you are also potentially infectious to a cabin full of people. Airlines can and do refuse passengers who appear acutely unwell at the gate, so turning up hoping to get through is a poor plan — you may lose the flight and the refund.
When not to fly
Do not fly, and see a doctor, if you are breathless at rest or on minimal exertion, coughing up blood, have chest pain that is worse on breathing in, have a high fever, are confused or drowsy, or if your lips or fingertips look blue. Pneumonia needs treating, not travelling.
Common questions
Can you fly with a chest infection?
There is no rule preventing it, but it is usually a poor idea. Reduced cabin oxygen on top of reduced lung function causes breathlessness, and congestion makes descent painful. Airlines can refuse a passenger who looks acutely unwell.
How long should I wait?
Until symptoms have largely settled and you can manage the CAA’s walking test comfortably. For a simple chest infection that is often one to two weeks; pneumonia takes considerably longer and should be reviewed by a doctor first.
Can I fly with bronchitis?
Same principles. Acute bronchitis with significant cough and congestion is worth delaying if you can. If you cannot, expect ear and sinus discomfort on descent and have pain relief with you.
What if I need to cancel?
Get it documented. A not fit to fly certificate is the evidence your insurer will ask for, and you should notify them and the operator as soon as you know.
Do I need oxygen on the flight?
Rarely for a simple infection in otherwise healthy lungs. If you have underlying lung disease as well, that changes things — see flying with COPD.
Related
Sources. The airline and clinical facts on this page were checked against these primary sources on 24 August 2026. Airline policies change without notice — always confirm with your airline before you book or travel.
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