Asthma:
In asthma, the trachea and alveolii get constricted as a reaction against external allergic substances such as dust, cotton, pollen, etc. or some internal allergen. As a result, respiration becomes acutely difficult. Asthma attacks occur mostly in the later part of the night or in the early morning.
The sufferer is compelled to get up from the bed and sit. He tries to breathe more freely by bending forward. After a few minutes or hours acute symptoms disappear, either on their own or by some remedies. Such attacks recur frequently.