Idiopathic pulmonary fibrosis (IPF) is a lung condition affecting more than 130,000 Americans. Still, IPF is a relatively unknown condition.

IPF causes tissue inside the lungs to scar and thicken. This scarring worsens over times. The damaged lung tissue can’t take in oxygen as efficiently, making it difficult to breathe. The term idiopathic means that, unlike some cases of pulmonary fibrosis, doctors aren’t able to pinpoint its exact cause.

Possible Causes

Depending on your medical history and lifestyle, there are many possible causes of IPF. In most cases, doctors don’t know exactly what causes pulmonary fibrosis. It’s likely caused by a combination of environmental and genetic factors.

Pollution and Toxins

Exposure to environmental, household, and occupational pollution is thought to contribute to IPF. The likelihood is higher with prolonged and long-term exposure. Some likely causes are:

  • asbestos
  • dust from silica and hard metals
  • bird droppings
  • household dust
  • grain and wood dust
  • dust, droppings, and particles from cattle and other types of farming
  • toxic fumes

Radiation Treatment

Radiation therapy near the chest, like that used to treat breast and lung cancers, can lead to scar tissue in the lung. The severity of the pulmonary fibrosis generally depends on how much of the lung was exposed to radiation, the length of treatment, and the level of radiation.

Prior or Existing Illness

Viral infections may be possible causes of IPF, such as:

There are other medical conditions that are associated with pulmonary fibrosis, such as tuberculosis, rheumatoid arthritis, and lupus. Gastroesophageal reflux disease (GERD) may also play a role. It’s thought that those who suffer from GERD may inhale droplets of stomach content into the lungs, leading to the formation of scar tissue.


Several medications are also believed to be associated with IPF. Some of these are the chemotherapy drugs methotrexate, bleomycin, and cyclophosphamide. Some heart medications may also be to blame, like the beta blocker propranolol and arrhythmia drug amiodarone. Another class of drugs studied for its role in idiopathic pulmonary fibrosis is antibiotics, particularly sulfasalazine and nitrofurantoin.

Genetic Factors

Little is known about the possible genetic component of IPF. While there seems to be a hereditary link or connection, more research is needed in this area.


The main symptom of IPF is shortness of breath. This comes from the lungs being unable to efficiently bring in oxygen and pass it into the bloodstream. Other symptoms include:

  • fatigue
  • weight loss not related to changes in diet or exercise
  • dry cough that persists for 30 days or more
  • a crackling sound in the lungs
  • muscle and joint aches and pain
  • enlarged, rounded fingertips and nails, known as clubbing

Risk Factors

Certain factors can increase your risk for developing IPF. These include:

  • age (between 40 and 70)
  • male gender
  • smoking cigarettes (previous or current)
  • working around pollution like dust or fumes
  • family history of IPF

While IPF is still poorly understood by both the general public and the medical community, there are a few organizations leading the fight for more research to search for a cure. As awareness is raised, and research advances, there’s hope that there will soon be greater knowledge of where this condition comes from, and how to combat it.