Explanation

If you have asthma, the cells in your lungs are sensitive. What happens is that you breathe in harmless particles, which then travel through your trachea and settle in your lungs.

Your lungs then react as if they are germs and alert your immune system. Your lungs become inflamed and fill up with mucous, making it hard to breathe.

Also, bronchoconstriction happens in your bronchi, making the space inside them smaller, so the air can't move through the airways.