Idiopathic pulmonary hemosiderosis (IPH) is a rare disease characterized by recurrent episodes of diffuse alveolar hemorrhage, or bleeding into the lungs. Patients typically present with shortness of breath, fever, cough, and hemoptysis. Chronic illness often results in malnutrition and failure to thrive, which is particularly pronounced in the pediatric patient population. Malaise from chronic blood loss anemia and iron deficiency can also be a hallmark symptom of IPH.

The etiology is poorly understood, but it is thought to result from immune dysregulation. IPH is very rare with an unknown prevalence. Most cases are described in children (80%) or young adults; however, patients of all ages have been diagnosed with IPH. Increased incidence among related individuals is suggestive of either environmental or genetic risk factors. To date, no known environmental or inheritable factor has been identified.

Although the body is able to reabsorb most of the blood from the lungs, a large amount of iron is often left behind. Over time, this iron can lead to pulmonary fibrosis and chronic lung disease. Severe anemia can also occur.