Coughing can occur alone, without the other symptoms of asthma that are usually present and recognized by the physician or patient. Cough variant asthma causes great difficulty for the physician to accurately diagnose the true underlying cause of the cough as being asthma because it can be easily confused with other conditions, such as chronic bronchitis and post nasal drip due to hay fever or sinus disease. Coughing can occur during day or night. Night time coughing is most disruptive, interfering with sleep.
Nocturnal or night time asthma may occur without any day time symptoms recognized by the patient. This is called “Nocturnal asthma”. The patient may have wheezing or shortness of breath when lying down, or may not notice these symptoms until awoken by them in the middle of the night, usually between 2 and 4 a.m. Nocturnal asthma may occur only once in a while, or frequently during the week. Night time symptoms may also be a common problem in people who have daytime asthma as well, but then it’s true nature is more readily recognized. When there are no day time symptoms to suggest asthma is an underlying cause of the nighttime cough, this type of asthma will be more difficult to recognize and usually delays proper therapy. The cause (or causes) of this phenomenon is unknown, although many possibilities are under investigation.
Shortness of breath or wheezing occurring after strenuous exercise is called exercise–induced asthma. Although this phenomenon happens in up to 80% of people with recognized asthma, it frequently takes place as an isolated event without any other symptoms of the disease at any other time. This complicates any diagnosis of asthma as an underlying cause because frequently, this form of asthma is confused with poor physical condition or possible heart problems. Nevertheless, asthma should always be suspected as a possible cause of exercise–induced wheezing or shortness of breath, especially when the person is otherwise healthy.