What is asthma, including its causes, symptoms, and cure?

**Asthma:** A chronic respiratory allergy where airways become inflamed and constricted. * **Causes (Triggers):** Dust, smoke, pollen, and cold air. * **Symptoms:** Wheezing, shortness of breath, and chest tightness. * **Cure:** No permanent cure; controlled using inhalers (bronchodilators).