GasMan. .. .The chances are that the crew would indeed land at the first opportunity if it were obviously a serious case, fuel dumping and all. Enroute medical diversions do happen. The assistance of any medically qualified persons on board will almost always be sought. If needed, most aircraft can obtain medical advice in flight via HF radio, if an airport is not close to hand, however, rather than risk someones life the crew will land at the nearest suitable airfield.