Rare diseases · Sign or symptom
Diffuse alveolar hemorrhage
HP:0025420
What it means
A type of of pulmonary hemorrhage that originates from the pulmonary microcirculation, including the alveolar capillaries, arterioles, and venules. It presents with hemoptysis, anemia, diffuse lung infiltration, and acute respiratory failure. The diagnosis is confirmed by the observation of the accumulation of red blood cells, fibrin, or hemosiderin-laden macrophage in the alveolar space on pathologic biopsy. Hemosiderin, a product of hemoglobin degradation, appears at least 48-72 hours after bleeding and is helpful in distinguishing diffuse alveolar hemorrhage from surgical trauma. Mild interstitial thickening, organizing pneumonia, or diffuse alveolar damage can also be seen.
Diffuse alveolar hemorrhage is a life-threatening and medical emergency that can be caused by numerous disorders and presents with hemoptysis, anemia, and diffuse alveolar infiltrates.
Rare diseases that can present with this10
Sometimes5–29%
5The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Diffuse alveolar haemorrhage
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.