Idiopathic pulmonary fibrosis is a serious lung disease. Idiopathic pulmonary fibrosis causes scar tissue to grow inside the lungs and makes it hard to breathe. When we breathe in the oxygen moves through tiny air sacs in the lungs and into the blood stream and finally reaches the organs. In idiopathic pulmonary fibrosis due to its scar tissues, it makes the lungs breathe harder.