A dry cough that has been bad for two months is clinically typical of a chronic cough, that is, a cough that lasts longer than two weeks. 2. gastroesophageal reflux disease: it can also cause a persistent dry cough and is often accompanied by acid reflux, belching and hiccups. 3. malignant tumors of the lung: it can also cause a persistent dry cough. Therefore, if the dry cough has been bad for two months, you need to improve the lung CT, allergen screening, lung function and bronchial excitation test in time to clarify the specific cause.