| Asthma | VCD | |
| Time of onset | Quick (within minutes) | Sudden onset (within seconds) |
| Duration | Minutes to hours | Seconds to a few minutes |
| Dyspnoea during | Expiration | Inspiration |
| Area of limitation | Thorax, lower airways | Throat |
| Inhaled drug therapy | Highly effective | Often ineffective, aggravating |
| Induced by | Irritants, allergens, exercise | Irritants, stress, exercise |