Can a cough alone be asthma? Cough variant asthma (CVA) is indicated if your cough is characterized by (1) chronic cough, i.e., coughing for more than 8 weeks; (2) often accompanied by significant nocturnal irritant cough; (3) ineffective conventional anti-cold and anti-infective treatment; (4) other causes of chronic cough have been ruled out; (5) bronchodilators, sugar corticosteroid treatment is effective. At this point, you should cooperate with the doctor to improve the examination and clarify the diagnosis.