The next day the patient may feel well enough to pursue his accustomed avocation, and may remain free from all symptoms of the disease until another attack comes on; but more frequently he is confined to the house, if not to bed, the slightest exertion being sufficient to cause dyspnoea; and during the following night there is a repetition of the paroxysm. If unchecked by treatment, the disease may continue for days, weeks, and in some instances even for months, the paroxysms often increasing in severity until, as in other nervous affections, it ultimately wears itself out. There is no regularity in the occurrence of the attacks. In some cases they recur every few days, while in others there may be an interval of weeks or months between the seizures. Even in the same case, although the individual paroxysms of the attack may come on at the same hour, there is, except in rare instances, no regularity in the recurrence of the attack itself; and when it does recur at a certain time it is almost always due to some cause which, as in hay asthma, exerts its influence only at that particular period. In the great majority of cases asthma comes on without any warning whatsoever, but occasionally it is preceded by certain sensations which to the experienced asthmatic are a sure indication that an attack is impending. With some it is only a feeling of ill-defined discomfort; others complain of various disorders of the digestive system--a sense of dryness of the mouth and pharynx, uncomfortable distension of the epigastrium with eructation of {186} gases from the stomach, and more or less obstinate constipation. A troublesome itching of the skin often precedes the attack. Some experience a feeling of constriction around the throat; a profuse secretion of clear urine is a symptom of this stage. Frequent gaping, frontal and occipital headache, are mentioned; but far more constant than all of these are certain symptoms indicative of a mild grade of acute catarrh of the respiratory organs--coryza, with swelling of the Schneiderian membrane and discharge from the nostrils, sneezing, redness of the conjunctivæ with increased lachrymation, and later, as the irritation extends downward, more or less cough.