Pax Responsibility to Declare Illness
 

I have failed to find anything in airline Conditions of Carriage referring to this in general.

I have an elderly relative (80s), rather frail and suffering from sttage 4 cancer and requiring dialysis every 2 days. He has travelled long-haul many times in the last decade but his health has deteriorated recently. His mobility (upon which most airlines cncentrate their attention) is not too bad, he might not even be a WCHR.
He plans a UK - AUS - UK trip later this summer, compelled by a wedding but I am concerned that this is not a good idea at all.
What is his responsibility (if any) to the Airline to inform them in advance of his condition - and what is the airline's likely action if he does not and is questioned about his health?

I have been looking at the British Airways site for info. It seems that the passenger should inform the airline of his conditions especially requiring dialysis. The dialysis per se is not an issue directly but if there are delays then he may need to go to hospital or use a portable dialysis machine. Depending on the other factors, breaking up the trip into 2 with a stopover may make it more tolerable.
You are right to be concerned. He should speak to his doctors as flying is quite stressful on the body, let alone the jetlag etc.
My grandfather was 85 when he decided to visit UK for the first time from Australia. Qantas insisted he got a medical clearance and the doc advised him that he needed a pacemaker fitted to fly. (He grumbled about it but got the pacemaker and had a great trip).

A colleague who had terminal pancreatic cancer was advised that even a short flight would be too much for his body to handle. (our company offered to fly him and his wife in a Hawker 800 for a quick jolly but the docs said no).

Get a doctors advice I'd say. Work college traveled across the Pacific to the US with a heart condition against his doctors advice, took ill in the US, thought he'd fly home to avoid high US medical expenses, died enroute.

There is no legal requirement for patients to disclose.

Most patients come to attention due to requesting help for mobility issues

If a doctor is arranging a flight they should inform the airline and complete a MEDIF form, but 99% are ignorant and dont

If the airline is aware they will either review in house (BA) or contract out and may decline to fly. Their main concern is the risk of diversion.

The issues that we are concerned about are

1 oxygenation - if patients have lung issues and become hypoxic on decompression it is a problem so we can test their lung function on reduced oxygen to simulate decompression

2 heart failure - decompression effectively pushes you towards this which is why your ankles swell

3 risk of loss of consciousness - fits, brain tumours, diabetes

and the BIG no no is visual - if the passenger might upset other passengers by their appearance.

Cancer in itself is not an issue but brain tumours and lung tumours are - see above. If dialysing you should dialyse immediately before the flight so you are not overloaded, and take off an extra volume of fluid.

Hope this helps