The major criterion for diagnosis is typically a confirmed surgical biopsy. Minor diagnostic criteria have been proposed for DIPNECH.

- Clinical presentation: woman, between the age of 45 and 67 with cough and/or shortness of breath for 5–10 years

- Pulmonary function: increased residual volume, increased total lung capacity, fixed obstruction, low diffusing capacity of the lung for carbon monoxide that corrects with alveolar volume

- High-resolution CT scan: diffuse pulmonary nodules 4–10 mm, greater than 20 nodules, mosaic attenuation or air trapping in greater than 50% of the lung

- Transbronchial biopsy: proliferation of pulmonary neuroendocrine cells

- Serum markers: elevated serum chromogranin A levels

Although some patients present with normal lung function, pulmonary function tests generally demonstrate fixed airway obstruction with a decreased FEV1 and reduced FEV1/FVC ratio without bronchodilator response. Air trapping is common and leads to increased residual volumes. As the disease progresses, a mixed pattern of obstruction and restriction may develop. In general the obstructive lung disease is slowly progressive with periods of stability.

For some types of chILD and few forms adult ILD genetic causes have been identified. These may be identified by blood tests. For a limited number of cases this is a definite advantage, as a precise molecular diagnosis can be done; frequently then there is no need for a lung biopsy. Testing is available for

Pulmonary function tests, arterial blood gases, ventilation perfusion relationships, and O2 diffusing capacity are normal in the initial stages of PAM. As the disease progresses, pulmonary function tests reveal typical features of a restrictive defect with reduced forced vital capacity (FVC) and elevated forced expiratory volume in FEV1/FVC.

The diagnosis can be confirmed by lung biopsy. A videoscopic assisted thoracoscopic wedge biopsy (VATS) under general anesthesia may be necessary to obtain enough tissue to make an accurate diagnosis. This kind of biopsy involves placement of several tubes through the chest wall, one of which is used to cut off a piece of lung to send for evaluation. The removed tissue is examined histopathologically by microscopy to confirm the presence and pattern of fibrosis as well as presence of other features that may indicate a specific cause e.g. specific types of mineral dust or possible response to therapy e.g. a pattern of so-called non-specific interstitial fibrosis.

Misdiagnosis is common because, while overall pulmonary fibrosis is not rare, each individual type of pulmonary fibrosis is uncommon and the evaluation of patients with these diseases is complex and requires a multidisciplinary approach. Terminology has been standardized but difficulties still exist in their application. Even experts may disagree with the classification of some cases.

On spirometry, as a restrictive lung disease, both the FEV1 (forced expiratory volume in 1 second) and FVC (forced vital capacity) are reduced so the FEV1/FVC ratio is normal or even increased in contrast to obstructive lung disease where this ratio is reduced. The values for residual volume and total lung capacity are generally decreased in restrictive lung disease.

On magnetic resonance imaging (MRI), the calcific lesions usually show hypointensity or a signal void on T1- and T2-weighted images.

Investigation is tailored towards the symptoms and signs. A proper and detailed history looking for the occupational exposures, and for signs of conditions listed above is the first and probably the most important part of the workup in patients with interstitial lung disease. Pulmonary function tests usually show a restrictive defect with decreased diffusion capacity (DLCO).

A lung biopsy is required if the clinical history and imaging are not clearly suggestive of a specific diagnosis or malignancy cannot otherwise be ruled out. In cases where a lung biopsy is indicated, a trans-bronchial biopsy is usually unhelpful, and a surgical lung biopsy is often required.

The diagnosis is usually suspected following a CT scan. Typical features on CT include solid and sub-solid nodules, ground glass change and reticulation. There may be features of multi-system involvement such as adenopathy and splenomegaly.

The commonest abnormality on lung function testing is a decrease in gas transfer. Both obstructive and restrictive patterns on spirometry have been reported.

The differential diagnosis includes infection, other interstitial lung diseases and malignant disease including lymphoma. Exclusion of infection is therefore an important step in management, but confirmation of the diagnosis requires lung biopsy. In people who have lung disease prior to a diagnosis of CVID, the differential diagnosis includes sarcoidosis. Sarcoid is also characterised by granulomatous involvement of the lung and therefore patients being investigated for sarcoid should have serum immunoglobulins measured to exclude CVID.

Chest x-rays of affected individuals typically reveal nonspecific alveolar opacities. Diagnosis is generally made by surgical or endoscopic biopsy of the lung, revealing the distinctive pathologic finding. The current gold standard of PAP diagnosis involves histopathological examination of alveolar specimens obtained from bronchoalveolar lavage and transbronchial lung biopsy.

Microscopically, the distal air spaces are filled with a granular, eosinophilic material that is positive with the PAS stain and the PAS diastase stain. The main histomorphologic differential diagnosis is pulmonary edema, which does not have dense bodies.

An ELISA to measure antibodies against GM-CSF has been validated for routine clinical diagnosis of autoimmune PAP.

The exact cause of rheumatoid lung disease is unknown. However, associated factors could be due largely to smoking. Sometimes, the medicines used to treat rheumatoid arthritis, especially methotrexate, may result in lung disease.

Prevention's:

- Stop smoking: Chemicals found in cigarettes can irritate already delicate lung tissue, leading to further complications.

- Having regular checkups: The doctor could listen to lungs and monitor breathing, because lung problems that are detected early can be easier to treat.

The diagnosis of RA was formerly based on detection of rheumatoid factor (RF). However, RF is also associated with other autoimmune diseases. The detection of anti-CCP is currently considered the most specific marker of RA. The diagnosis of rheumatoid lung disease is based on evaluation of pulmonary function, radiology, serology and lung biopsy. High resolution CT scans are preferred to chest X-rays due to their sensitivity and specificity.

Associated doctors to diagnosis this properly would be a Rheumatologists or Pulmonologist.

Within a physical examination doctors could find possible indications, such as hearing crackles (rales) when listening to the lungs with a stethoscope. Or, there may be decreased breath sounds, wheezing, a rubbing sound, or normal breath sounds. When listening to the heart, there may be abnormal heart sounds. Bronchoscopic, video-assisted, or open lung biopsy allows the histological characterization of pulmonary lesions, which can distinguish rheumatoid lung disease from other interstitial lung diseases.

The following tests may also show signs of rheumatoid lung disease:

- Chest x-ray may show:

- pleural effusion

- lower zone predominant reticular or reticulonodular pattern

- volume loss in advanced disease

- skeletal changes, e.g. erosion of clavicles, glenohumeral erosive arthropathy, superior rib notching

- Chest CT or HRCT features include:

- pleural thickening or effusion

- interstitial fibrosis

- bronchiectasis

- bronchiolitis obliterans

- large rheumatoid nodules

- single or multiple

- tend to be based peripherally

- may cavitate (necrobiotic lung nodules)

- cavitation of a peripheral nodule can lead to pneumothorax or haemopneumothorax.

- follicular bronchiolitis

- small centrilobular nodules or tree-in-bud

- rare

- Caplan syndrome

- Echocardiogram (may show pulmonary hypertension)

- Lung biopsy (bronchoscopic, video-assisted, or open), which may show pulmonary lesions

- Lung function tests

- Needle inserted into the fluid around the lung (thoracentesis)

- Blood tests for rheumatoid arthritis

Respiratory diseases may be investigated by performing one or more of the following tests

- Biopsy of the lung or pleura

- Blood test

- Bronchoscopy

- Chest x-ray

- Computed tomography scan, including high-resolution computed tomography

- Culture of microorganisms from secretions such as sputum

- Ultrasound scanning can be useful to detect fluid such as pleural effusion

- Pulmonary function test

- Ventilation—perfusion scan

Multiple abnormal laboratory findings have been noted in indium lung. High levels of serum indium have been found in all cases of indium lung. Other abnormal laboratory values that have been found include elevated alanine aminotransferase, elevated aspartate aminotransferase, elevated C-reactive protein, elevated interstitial lung disease markers, and elevated GM-CSF autoantibodies.

CT scanning and radiography can be used to aid in the diagnosis of indium lung. CT abnormalities include ground-glass opacities, interlobular septal thickening, honeycombing, and bronchiectasis.

Hypoxia caused by pulmonary fibrosis can lead to pulmonary hypertension, which, in turn, can lead to heart failure of the right ventricle. Hypoxia can be prevented with oxygen supplementation.

Pulmonary fibrosis may also result in an increased risk for pulmonary emboli, which can be prevented by anticoagulants.

Flavorings-related lung disease can be prevented with the use of engineering controls (e.g. exhaust hoods or closed systems), personal protective equipment, monitoring of potentially affected workers, worker education, and by not using lung-disease-causing flavorings.

The definitive diagnosis is rendered by a microscopic examination, after excision. Typical carcinoids have cells with stippled chromatin and a moderate quantity of cytoplasm. They typically have few mitoses and lack necrosis. By definition, they are greater than 4 mm in largest dimension; smaller lesions are referred to as "pulmonary carcinoid tumourlets".

The differential diagnosis of typical pulmonary carcinoid tumour includes: "atypical pulmonary carcinoid tumour", "pulmonary carcinoid tumourlet" and "lung adenocarcinoma".

Respiratory disease is a common and significant cause of illness and death around the world. In the US, approximately 1 billion "common colds" occur each year. A study found that in 2010, there were approximately 6.8 million emergency department visits for respiratory disorders in the U.S. for patients under the age of 18. In 2012, respiratory conditions were the most frequent reasons for hospital stays among children.

In the UK, approximately 1 in 7 individuals are affected by some form of chronic lung disease, most commonly chronic obstructive pulmonary disease, which includes asthma, chronic bronchitis and emphysema.

Respiratory diseases (including lung cancer) are responsible for over 10% of hospitalizations and over 16% of deaths in Canada.

In 2011, respiratory disease with ventilator support accounted for 93.3% of ICU utilization in the United States.

There is very little information written by, and for patients with GLILD. However, interest in the condition is increasing and multi-centre studies such as STILPAD are in progress.

The first advance in the treatment of pulmonary alveolar proteinosis came in November 1960, when Dr. Jose Ramirez-Rivera at the Veterans' Administration Hospital in Baltimore applied repeated "segmental flooding" as a means of physically removing the accumulated alveolar material.

The standard treatment for PAP is whole-lung lavage, in which the lung is filled with sterile fluid with subsequent removal of the fluid along with the abnormal surfactant material. This is generally effective at improving PAP symptoms, often for a prolonged period of time. Since the mouse discovery noted above, the use of GM-CSF injections has also been attempted, with variable success. Lung transplantation can be performed in refractory cases.

Bronchiolitis obliterans is often misdiagnosed as asthma, chronic bronchitis, emphysema or pneumonia.

Several tests are often needed to correctly diagnose bronchiolitis obliterans, including chest X-rays, diffusing capacity of the lung tests (DLCO), spirometry, lung volume tests, high-resolution CT (HRCT), and lung biopsy. Diffusing capacity of the lung (DLCO) tests are usually normal; people with early-stage BO are more likely to have normal DLCO. Spirometry tests usually show fixed airway obstructions and sometimes restriction, where the lungs can't expand fully. Lung volume tests may show hyperinflation (excessive air in lungs caused by air trapping). HRCT can also show air trapping when the person being scanned breathes out completely; it can also show thickening in the airway and haziness in the lungs. Transthoracic lung biopsies are preferable for diagnosis of constrictive BO compared to transbronchial biopsies; regardless of the type of biopsy, a diagnosis may only be achieved by examination of multiple samples.

Oral propranolol appears to be the most effective treatment for reducing the size of capillary hemangiomas in children and is more effective than placebo, observation without intervention, or oral corticosteroids.

Asbestos can cause lung cancer that is identical to lung cancer from other causes. Exposure to asbestos is associated with all major histological types of lung carcinoma (adenocarcinoma, squamous cell carcinoma, large-cell carcinoma and small-cell carcinoma). The latency period between exposure and development of lung cancer is 20 to 30 years. It is estimated that 3%-8% of all lung cancers are related to asbestos. The risk of developing lung cancer depends on the level, duration, and frequency of asbestos exposure (cumulative exposure). Smoking and individual susceptibility are other contributing factors towards lung cancer. Smokers who have been exposed to asbestos are at far greater risk of lung cancer. Smoking and asbestos exposure have a multiplicative (synergistic) effect on the risk of lung cancer. Symptoms include chronic cough, chest pain, breathlessness, haemoptysis (coughing up blood), wheezing or hoarseness of the voice, weight loss and fatigue. Treatment involves surgical removal of the cancer, chemotherapy, radiotherapy, or a combination of these (multimodality treatment). Prognosis is generally poor unless the cancer is detected in its early stages. Out of all patients diagnosed with lung cancer, only 15% survive for five years after diagnosis.

Lung carcinoids typically present with a cough or hemoptysis. Findings may closely mimic malignant tumours of the lung, i.e. lung cancer.

Diagnosis can be hinted by high recurrence rates of lung collapse in a woman of reproductive age with endometriosis. CA-125 is elevated. Video-assisted thoracoscopy is used for confirmation.