Asthma (or Asthma bronchiale) is a disease that hurts the airways inside the lungs. It causes the tissue inside the airways to swell. Asthma also causes the bands of muscle around the airways to become narrow. This makes it hard for enough air to pass through and for the person to breathe normally. Asthma also causes mucus-making cells inside the airways to make more mucus than normal. This blocks the airways, which are already very narrow during an asthma attack, and makes it even more difficult to breathe.