Diagnosis of asthma is not directly related to sleep apnoea study. But asthma is a risk factor of development of sleep apnoea. In recent studies its found a bi-directional link between asthma and obstructive sleep apnea, due to the fact that both conditions involve swelling in the respiratory tract.When OSA closes the airway, the muscles receive a brain signal to reopen, which can cause friction and swelling in the airway tissue. Airway tissue in asthmatics is easily irritated, so a cycle of more inflammation, mucus production and decreased lung function begins. The two conditions together can cause serious health risks, even death in an untreated asthma attack. If you are suffering from disturbed sleep or breathing problems increased during sleep its recommended to take a sleep apnoea test to diagnose it. nCPAP therapy can be used safely in treating patients with OSA and coexisting asthma. Furthermore, nCPAP treatment improves the asthma control and, in particular, the nocturnal attacks.