Affected workers should be offered alternative employment. Continued exposure leads to development of persistent symptoms and progressive decline in FEV1.

There are three basic criteria for the diagnosis of CWP:

1. Chest radiography consistent with CWP

2. An exposure history to coal dust (typically underground coal mining) of sufficient amount and latency

3. Exclusion of alternative diagnoses (mimics of CWP)

Symptoms and pulmonary function testing relate to the degree of respiratory impairment but are not part of the diagnostic criteria. As noted above, the chest X-ray appearance for CWP can be virtually indistinguishable from silicosis. Chest CT, particularly high-resolution scanning (HRCT), are more sensitive than plain X-ray for detecting the small round opacities.

There are three key elements to the diagnosis of silicosis. First, the patient history should reveal exposure to sufficient silica dust to cause this illness. Second, chest imaging (usually chest x-ray) that reveals findings consistent with silicosis. Third, there are no underlying illnesses that are more likely to be causing the abnormalities. Physical examination is usually unremarkable unless there is complicated disease. Also, the examination findings are not specific for silicosis. Pulmonary function testing may reveal airflow limitation, restrictive defects, reduced diffusion capacity, mixed defects, or may be normal (especially without complicated disease). Most cases of silicosis do not require tissue biopsy for diagnosis, but this may be necessary in some cases, primarily to exclude other conditions.

For uncomplicated silicosis, chest x-ray will confirm the presence of small ( 1 cm) occurs from coalescence of small opacities, particularly in the upper lung zones. With retraction of the lung tissue, there is compensatory emphysema. Enlargement of the hilum is common with chronic and accelerated silicosis. In about 5–10% of cases, the nodes will calcify circumferentially, producing so-called "eggshell" calcification. This finding is not pathognomonic (diagnostic) of silicosis. In some cases, the pulmonary nodules may also become calcified.

A computed tomography or CT scan can also provide a mode detailed analysis of the lungs, and can reveal cavitation due to concomitant mycobacterial infection.

The best way to prevent silicosis is to identify work-place activities that produce respirable crystalline silica dust and then to eliminate or control the dust ("primary prevention"). Water spray is often used where dust emanates. Dust can also be controlled through dry air filtering.

Following observations on industry workers in Lucknow (India), experiments on rats found that jaggery (a traditional sugar) had a preventive action against silicosis.

Patient history should reveal exposure to cotton, flax, hemp, or jute dust. Diagnostic tests include a lung function test and a chest x ray or CT scan.

Measurable change in lung function before and after working shifts is key to diagnosis. Patients suffering from byssinosis show a significant drop in FEV1 over the course of work shift.

Chest radiographs show areas of opacity due to fibrosis of the pulmonary parenchyma.

Positive indications on patient assessment:

- Shortness of breath

- Chest X-ray may show a characteristic patchy, subpleural, bibasilar interstitial infiltrates or small cystic radiolucencies called honeycombing.

Pneumoconiosis in combination with multiple pulmonary rheumatoid nodules in rheumatoid arthritis patients is known as Caplan's syndrome.

According to the American Thoracic Society (ATS), the general diagnostic criteria for asbestosis are:

- Evidence of structural pathology consistent with asbestosis, as documented by imaging or histology

- Evidence of causation by asbestos as documented by the occupational and environmental history, markers of exposure (usually pleural plaques), recovery of asbestos bodies, or other means

- Exclusion of alternative plausible causes for the findings

The abnormal chest x-ray and its interpretation remain the most important factors in establishing the presence of pulmonary fibrosis. The findings usually appear as small, irregular parenchymal opacities, primarily in the lung bases. Using the ILO Classification system, "s", "t", and/or "u" opacities predominate. CT or high-resolution CT (HRCT) are more sensitive than plain radiography at detecting pulmonary fibrosis (as well as any underlying pleural changes). More than 50% of people affected with asbestosis develop plaques in the parietal pleura, the space between the chest wall and lungs. Once apparent, the radiographic findings in asbestosis may slowly progress or remain static, even in the absence of further asbestos exposure. Rapid progression suggests an alternative diagnosis.

Asbestosis resembles many other diffuse interstitial lung diseases, including other pneumoconiosis. The differential diagnosis includes idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis, sarcoidosis, and others. The presence of pleural plaquing may provide supportive evidence of causation by asbestos. Although lung biopsy is usually not necessary, the presence of asbestos bodies in association with pulmonary fibrosis establishes the diagnosis. Conversely, interstitial pulmonary fibrosis in the absence of asbestos bodies is most likely not asbestosis. Asbestos bodies in the absence of fibrosis indicate exposure, not disease.

The following are precautionary measures that can be taken to avoid the spread of bagassosis:

1. Dust control-prevention /suppression of dust such as wet process, enclosed apparatus, exhaust ventilation etc. should be used

2. Personal protection- masks/ respirators

3. Medical control- initial medical examination & periodical checkups of workers

4. Bagasse control- keep moisture content above 20% and spray bagasse with 2% propionic acid

COPD may need to be differentiated from other causes of shortness of breath such as congestive heart failure, pulmonary embolism, pneumonia, or pneumothorax. Many people with COPD mistakenly think they have asthma. The distinction between asthma and COPD is made on the basis of the symptoms, smoking history, and whether airflow limitation is reversible with bronchodilators at spirometry. Tuberculosis may also present with a chronic cough and should be considered in locations where it is common. Less common conditions that may present similarly include bronchopulmonary dysplasia and obliterative bronchiolitis. Chronic bronchitis may occur with normal airflow and in this situation it is not classified as COPD.

A chest X-ray and complete blood count may be useful to exclude other conditions at the time of diagnosis. Characteristic signs on X-ray are overexpanded lungs, a flattened diaphragm, increased retrosternal airspace, and bullae, while it can help exclude other lung diseases, such as pneumonia, pulmonary edema, or a pneumothorax. A high-resolution computed tomography scan of the chest may show the distribution of emphysema throughout the lungs and can also be useful to exclude other lung diseases. Unless surgery is planned, however, this rarely affects management. An analysis of arterial blood is used to determine the need for oxygen; this is recommended in those with an FEV less than 35% predicted, those with a peripheral oxygen saturation less than 92%, and those with symptoms of congestive heart failure. In areas of the world where alpha-1 antitrypsin deficiency is common, people with COPD (particularly those below the age of 45 and with emphysema affecting the lower parts of the lungs) should be considered for testing.

Health care professionals are at risk of occupational influenza exposure; during a pandemic influenza, anyone in a close environment is at risk, including those in an office environment.

Diagnosis of occupational asthma uses several techniques.

A non-specific bronchial hyperreactivity test can be used to help diagnose occupational asthma. It involves testing with methacholine, after which the forced expiratory volume in 1 second (FEV) of the patient is measured. This test is often used for measuring the intensity of a person's asthma and to confirm that the person needs to be treated for asthma.

Other non specific tests could require the patient to run for a few minutes at a continuous pace. In this case, the individual’s peak expiratory flow rate (PEFR) is measured, showing how fast a person can exhale. PEFR can also be measured at work to see if there is a difference from the PEFR in a controlled environment. Measuring PEFR at work is a highly reliable test for occupational asthma.

A skin prick test is usually performed on the inner forearm where a grid is marked and a drop of the allergens to be tested are placed on the arm in the grid. Once this has been done, the skin is pricked through the drop using a lancet. Reactions, if any, occur within 10 to 15 minutes and these results can then be analyzed.

Immunoglobulin E is an antibody found in human blood and is effective against toxins. Since it can also trigger allergic reactions to specific allergens like pollen, the IgE test is performed to evaluate whether the subject is allergic to these substances.

A spirometer is a device used to measure timed expired and inspired volumes, and can be used to help diagnose occupational asthma.

Specific inhalation challenges test for reactions to substances found in the workplace. One method is a whole body sealed chamber where the patient is exposed to articles that are present in their workplace. This method has the advantage of being able to assess, albeit highly subjectively, ocular and nasal symptoms as well as a reduction in FEV. Another test requires the patient to breathe aerosols of the suspected asthmagens through an oro-facial mask. These asthmagens are aerosolized using closed circuit chambers, and the quantities and concentrations administered are minute and extremely stable, to minimize the risk of exaggerated responses.

There is no cure available for asbestosis. Oxygen therapy at home is often necessary to relieve the shortness of breath and correct underlying low blood oxygen levels. Supportive treatment of symptoms includes respiratory physiotherapy to remove secretions from the lungs by postural drainage, chest percussion, and vibration. Nebulized medications may be prescribed in order to loosen secretions or treat underlying chronic obstructive pulmonary disease. Immunization against pneumococcal pneumonia and annual influenza vaccination is administered due to increased sensitivity to the diseases. Those with asbestosis are at increased risk for certain cancers. If the person smokes, quitting the habit reduces further damage. Periodic pulmonary function tests, chest x-rays, and clinical evaluations, including cancer screening/evaluations, are given to detect additional hazards.

Prevention of occupational asthma can be accomplished through better education of workers, management, unions and medical professionals. This will enable them to identify the risk factors and put in place preventive measures, including respiratory protection and exposure limits.

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.

Tuberculosis is a lung disease endemic in many parts of the world. Health care professionals and prison guards are at high risk for occupational exposure to tuberculosis, since they work with populations with high rates of the disease.

In 2013 CWP resulted in 25,000 deaths down from 29,000 deaths in 1990. Between 1970–1974, prevalence of CWP among US coal miners who had worked over 25 years was 32%; the same group saw a prevalence of 9% in 2005–2006.

The diagnosis of plastic bronchitis is confirmed by recovery of casts that have been coughed up or visualized during a bronchoscopy. There is no specific cytologic, pathologic or laboratory test that is diagnostic for casts due to lymphatic PB.

Bronchiectasis may be diagnosed clinically or on review of imaging. The British Thoracic Society recommends all non-cystic-fibrosis-related bronchiectasis be confirmed by CT. CT may reveal tree-in-bud abnormalities, dilated bronchi, and cysts with defined borders.

Other investigations typically performed at diagnosis include blood tests, sputum cultures, and sometimes tests for specific genetic disorders.

Eosinophilic pneumonia is diagnosed in one of three circumstances: when a complete blood count reveals increased eosinophils and a chest x-ray or computed tomography (CT) identifies abnormalities in the lung, when a biopsy identifies increased eosinophils in lung tissue, or when increased eosinophils are found in fluid obtained by a bronchoscopy (bronchoalveolar lavage [BAL] fluid). Association with medication or cancer is usually apparent after review of a person's medical history. Specific parasitic infections are diagnosed after examining a person's exposure to common parasites and performing laboratory tests to look for likely causes. If no underlying cause is found, a diagnosis of AEP or CEP is made based upon the following criteria. AEP is most likely with respiratory failure after an acute febrile illness of usually less than one week, changes in multiple areas and fluid in the area surrounding the lungs on a chest x-ray, and greater than 25% eosinophils on a BAL. Other typical laboratory abnormalities include an elevated white blood cell count, erythrocyte sedimentation rate, and immunoglobulin G level. Pulmonary function testing usually reveals a restrictive process with reduced diffusion capacity for carbon monoxide. CEP is most likely when the symptoms have been present for more than a month. Laboratory tests typical of CEP include increased blood eosinophils, a high erythrocyte sedimentation rate, iron deficiency anemia, and increased platelets. A chest x-ray can show abnormalities anywhere, but the most specific finding is increased shadow in the periphery of the lung, away from the heart.

Simple chest roentenograms may reveal collapse due to airway obstruction. The contralateral lung may be hyperinflated. Casts can be visualized within the major airways using computerized axial tomography scans.

Heavy T2-weighted MRI, and, as appropriate, intranodal lymphangiogram and/or dynamic contrast-enhanced MR lymphangiography may be useful for identifying pathological lymphatic tissue and/or lymphatic flow.

Owners often notice their cat coughing several times per day. Cat coughing sounds different from human coughing, usually sounding more like the cat is passing a hairball. Veterinarians will classify the severity of feline asthma based on the medical signs. There are a number of diseases that are very closely related to feline asthma which must be ruled out before asthma can be diagnosed. Lungworms, heartworms, upper and lower respiratory infections, lung cancer, cardiomyopathy and lymphocytic plasmacytic stomatitis all mimic asthmatic symptoms. Medical signs, pulmonary radiographs, and a positive response to steroids help confirm the diagnosis.

While radiographs can be helpful for diagnosis, airway sampling through transtracheal wash or bronchoalveolar lavage is often necessary. More recently, computed tomography has been found to be more readily available and accurate in distinguishing feline tracheobronchitis from bronchopneumonia.

The diagnostic criteria for acute exacerbation of COPD generally include a production of sputum that is purulent and may be thicker than usual, but without evidence of pneumonia (which involves mainly the alveoli rather than the bronchi). Also, diagnostic criteria may include an increase in frequency and severity of coughing, as well as increased shortness of breath.

A chest X-ray is usually performed on people with fever and, especially, hemoptysis (blood in the sputum), to rule out pneumonia and get information on the severity of the exacerbation. Hemoptysis may also indicate other, potentially fatal, medical conditions.

A history of exposure to potential causes and evaluation of symptoms may help in revealing the cause the exacerbation, which helps in choosing the best treatment. A sputum culture can specify which strain is causing a bacterial AECB. An early morning sample is preferred.

E-nose showed the ability to smell the cause of the exacerbation.

The definition of a COPD exacerbation is commonly described as "lost in translation," meaning that there is no universally accepted standard with regard to defining an acute exacerbation of COPD. Many organizations consider it a priority to create such a standard, as it would be a major step forward in the diagnosis and quality of treatment of COPD.

General treatment principles are removal from exposure, protection of the airway (i.e., preemptive intubation), and treatment of hypoxemia. Concomitant airway injury with acute bronchospasm often warrants treatment with bronchodilators because of the airway obstruction.

A beneficial role for corticosteroids has not been established by controlled trials in humans. Despite the lack of controlled evidence of efficacy, anecdotal reports of benefits from systemic corticosteroid use continue to appear.

Prophylactic antibiotic drugs have not proved to be efficacious in toxic lung injury. Antibiotics should be reserved for those patients with clinical evidence of infection.

In the differential diagnosis (finding the correct diagnosis between diseases that have overlapping features) of some obstructive lung diseases, DPB is often considered. A number of DPB symptoms resemble those found with other obstructive lung diseases such as asthma, chronic bronchitis, and emphysema. Wheezing, coughing with sputum production, and shortness of breath are common symptoms in such diseases, and obstructive respiratory functional impairment is found on pulmonary function testing. Cystic fibrosis, like DPB, causes severe lung inflammation, excess mucus production, and infection; but DPB does not cause disturbances of the pancreas nor the electrolytes, as does CF, so the two diseases are different and probably unrelated. DPB is distinguished by the presence of lesions that appear on X-rays as nodules in the bronchioles of both lungs; inflammation in all tissue layers of the respiratory bronchioles; and its higher prevalence among individuals with East Asian lineage.

DPB and bronchiolitis obliterans are two forms of primary bronchiolitis. Specific overlapping features of both diseases include strong cough with large amounts of often pus-filled sputum; nodules viewable on lung X-rays in the lower bronchi and bronchiolar area; and chronic sinusitis. In DPB, the nodules are more restricted to the respiratory bronchioles, while in OB they are often found in the membranous bronchioles (the initial non-cartilaginous section of the bronchiole, that divides from the tertiary bronchus) up to the secondary bronchus. OB is a bronchiolar disease with worldwide prevalence, while DPB has more localized prevalence, predominantly in Japan. Prior to clinical recognition of DPB in recent years, it was often misdiagnosed as bronchiectasia, COPD, IPF, phthisis miliaris, sarcoidosis or alveolar cell carcinoma.