A third of severe asthma sufferers have been put on a life support machine as the result of an asthma attack, figures show.
Research found that 28% of sufferers have experienced a potentially fatal attack which led to them being put on the life-saving machines.
Of those who suffer from the chronic inflammatory disease, over half live in fear of the next asthma attack, a survey found.
The figures, collated from 333 sufferers, found that two fifths of people with severe asthma have to visit accident and emergency units at least once a year.
Meanwhile a third have been admitted to hospital at least once in the last year, the research conducted by Novartis Pharmaceuticals found.
Dr Dinesh Saralaya, consultant respiratory physician at Bradford Teaching Hospitals NHS Foundation Trust, said: "People with severe asthma whose asthma is not under control or who are experiencing regular attacks should discuss how to best manage the condition with their doctor.
"This is a key goal, since the majority of sufferers feel they can get on with life if their symptoms are controlled adequately.
"There are options available that can help them to lead full and happy lives, thereby reducing the economic and personal burden of this condition."