Pulmonary fibrosis has serious complications, many of which can cause death. When your lungs cannot efficiently supply oxygen to your body anymore, you may develop a condition called hypoxemia, which means there is not enough oxygen in your bloodstream. At best, hypoxemia throws off your body's normal functioning processes, and at worse, it leads to respiratory failure, the most common cause of death in people who have pulmonary fibrosis. You may also develop pulmonary hypertension as a result of the disease, which is high blood pressure in the blood vessels in your lungs. This occurs when the scar tissue from pulmonary fibrosis presses on your blood vessels, which makes it harder for blood to flow through them. Pulmonary hypertension can lead to heart failure because the heart has to work overtime to push blood through the blood vessels in your lungs. If you think you are experiencing any of these conditions, seek immediately medical help.