[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Lung](https://durgical.com/en/general-pathology/areas/lung/) › Diffuse alveolar hemorrhage

# Diffuse alveolar hemorrhage

- Lesion

Bleeding into many alveoli at once, from autoimmune attack on the basement membrane or from capillaritis. It shows as hemoptysis, anaemia and hemosiderin.

Updated Nov 12, 2026

## Key points

- Goodpasture: antibodies against the noncollagenous domain of the α3 chain of type IV collagen; linear IgG along alveolar and glomerular basement membranes.
- Goodpasture typically affects young men who smoke; HLA-DRB1*15 association.
- GPA: upper airway, lung and kidney; capillaritis and scattered poorly formed granulomas; PR3-ANCA (c-ANCA).
- Idiopathic pulmonary hemosiderosis: young children; recurrent hemorrhage, iron-deficiency anaemia, no antibodies.
- Hemosiderin-laden macrophages (Prussian blue positive) in lavage prove repeated bleeding.

On this page

- The basics Key points
- What it is
- Structure
- Step by step
- Causes of diffuse alveolar hemorrhage
- Markers
- Memory aid
- Elsewhere in DurgiPedia

- Clinical Clinical notes

- Study Test yourself

- Connections Connections

## What it is

Diffuse pulmonary hemorrhage syndromes flood the alveoli with blood. Three groups matter: anti-glomerular basement membrane disease with lung involvement (Goodpasture syndrome), vasculitis-associated hemorrhage (granulomatosis with polyangiitis, microscopic polyangiitis, lupus) and idiopathic pulmonary hemosiderosis. Pulmonary-renal syndromes (lung hemorrhage plus rapidly progressive glomerulonephritis) are emergencies.

## Structure

- Gross: heavy lungs with red-brown consolidation.
- H&E: blood in alveoli, focal necrosis of alveolar walls, many hemosiderin-laden macrophages; later septal fibrosis and type II hyperplasia.
- Immunofluorescence (Goodpasture): linear IgG and complement along basement membranes.
- GPA: neutrophilic capillaritis, necrotising vasculitis, geographic necrosis and poorly formed granulomas with giant cells.

## Step by step

- Autoantibodies (anti-GBM) or ANCA-activated neutrophils attack the alveolar capillary wall.
- In Goodpasture, smoke or infection may expose the hidden collagen epitope in the lung.
- Complement and neutrophils destroy the capillaries (capillaritis) and the basement membrane.
- Red cells pour into the alveoli; macrophages ingest them and convert haem iron to hemosiderin.
- The same attack in glomeruli causes crescentic glomerulonephritis.
- Repeated episodes leave fibrosis and iron deficiency.

## Causes of diffuse alveolar hemorrhage

| Disease | Antibody | Immunofluorescence | Other clues |
| --- | --- | --- | --- |
| [Anti-GBM (Goodpasture)](https://durgical.com/en/conditions/rapidly-progressive-glomerulonephritis/) | Anti-α3 type IV collagen | Linear IgG | Young male smokers, renal failure |
| [Granulomatosis with polyangiitis](https://durgical.com/en/conditions/granulomatosis-with-polyangiitis/) | PR3-ANCA | Pauci-immune | Sinusitis, nasal destruction, granulomas |
| [Microscopic polyangiitis](https://durgical.com/en/conditions/microscopic-polyangiitis/) | MPO-ANCA | Pauci-immune | No granulomas |
| [Systemic lupus erythematosus](https://durgical.com/en/conditions/systemic-lupus-erythematosus/) | ANA, anti-dsDNA | Granular immune complexes | Other lupus features |
| Idiopathic pulmonary hemosiderosis | None | Negative | Young children, anaemia |

## Markers

- Prussian blue
- Linear IgG
- PR3-ANCA
- MPO-ANCA

## Clinical notes

- Hemoptysis (sometimes absent despite major bleeding), falling haemoglobin, new bilateral infiltrates, rising DLCO.
- Check urine sediment and creatinine; test anti-GBM and ANCA.
- Treatment: plasma exchange (anti-GBM) and immunosuppression; outcomes improve with early diagnosis.

## Memory aid

Linear for Goodpasture, little (pauci) for ANCA, lumpy (granular) for lupus.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the target antigen in Goodpasture syndrome?

The noncollagenous domain of the α3 chain of type IV collagen in glomerular and alveolar basement membranes.

## What immunofluorescence pattern does anti-GBM disease show?

Linear deposits of IgG (and complement) along the basement membranes.

## Which cells prove repeated alveolar bleeding, and how are they shown?

Hemosiderin-laden macrophages, highlighted blue by the Prussian blue iron stain.

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## Elsewhere in DurgiPedia

- [Type II hypersensitivity (antibody against cells)](https://durgical.com/en/immunology/type-ii-hypersensitivity/)

## Connections

## Related 4

- [Hemorrhage: petechiae, purpura, ecchymosis, hematoma, and what blood loss does](https://durgical.com/en/general-pathology/hemorrhage-petechiae-purpura-ecchymosis-hematoma-and-what-blood-loss-does/)
- [Pulmonary edema: hemodynamic vs alveolar-capillary injury](https://durgical.com/en/general-pathology/pulmonary-edema-hemodynamic-vs-alveolar-capillary-injury/)
- [Necrotizing lesions of the nose and upper airway](https://durgical.com/en/general-pathology/necrotizing-lesions-of-the-nose-and-upper-airway/)
- [Pigments in tissue: lipofuscin, hemosiderin, melanin, bilirubin, carbon](https://durgical.com/en/general-pathology/pigments-in-tissue-lipofuscin-hemosiderin-melanin-bilirubin-carbon/)

## Related conditions 4

- [Rapidly progressive glomerulonephritis (anti-GBM, ANCA)](https://durgical.com/en/conditions/rapidly-progressive-glomerulonephritis/)
- [Granulomatosis with polyangiitis](https://durgical.com/en/conditions/granulomatosis-with-polyangiitis/)
- [Microscopic polyangiitis](https://durgical.com/en/conditions/microscopic-polyangiitis/)
- [Systemic lupus erythematosus](https://durgical.com/en/conditions/systemic-lupus-erythematosus/)

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Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Lung Diseases](https://medlineplus.gov/lungdiseases.html) (MedlinePlus, US National Library of Medicine, 2025).

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Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/diffuse-alveolar-hemorrhage/