Asthma is a chronic lung disease that inflames and narrows the airways, affecting 26 million people in the US, many of whom are unaware. Common symptoms include coughing, shortness of breath, chest tightness, and wheezing, which can be triggered by allergens, irritants, weather conditions, illness, or exercise. Any asthma symptoms can become serious or deadly if left untreated.

1. Overview
Asthma is a chronic lung disease that inflames and
narrows the airways in the lungs. In the United States
asthma affects an estimated 26 million people — many
of whom aren’t aware that they have it, especiallyif their
symptomsaren’t severe.
The most commonsymptoms are:
 Coughing, especially at night, during exercise or when
laughing

2.  Shortness of breath
 Chest tightness
 Wheezing (a whistling or squeakysound in your chest
when you breathe, especiallywhen exhaling)
 Any asthma symptom is serious and can become
deadly if left untreated.
Symptoms may be triggered by exposure to an allergen
(such as ragweed, pollen, pet hair or dust mites), irritants
in the air (such as smoke, chemicalfumes or strong
odors) or extreme weatherconditions. Illness —
particularlya respiratory illness or the flu — and exercise
can also make you more susceptible.