Sometimes adults get asthma even though they didn't have it as children. When an allergen or an irritant affects your airways and triggers an asthma attack, you will usually feel an increase in some signs such as chest tightness, shortness of breath, cough, wheezing and, sometimes, a feeling of chest congestion caused by increased mucus in your airways. If you are measuring your peak flow rate every day, watch for a drop in the morning measurement from your usual value. Asthma attacks can be mild or severe. They may develop suddenly or more slowly.
Severe signs suggest a severe attack.
This requires medical care right away. It's important not to wait to get emergency care, because a severe asthma attack can be life-threatening. Sometimes a mild attack that seems to go away can come back several hours later. This is called a late-phase attack. It can be more severe than the first attack.