Pulmonary ultrasound, performed at the bedside or on the accident scene, is being explored as a diagnosis for pulmonary contusion. Its use is still not widespread, being limited to facilities which are comfortable with its use for other applications, like pneumothorax, airway management, and hemothorax. Accuracy has been found to be comparable to CT scanning.

Computed tomography (CT scanning) is a more sensitive test for pulmonary contusion, and it can identify abdominal, chest, or other injuries that accompany the contusion. In one study, chest X-ray detected pulmonary contusions in 16.3% of people with serious blunt trauma, while CT detected them in 31.2% of the same people. Unlike X-ray, CT scanning can detect the contusion almost immediately after the injury. However, in both X-ray and CT a contusion may become more visible over the first 24–48 hours after trauma as bleeding and edema into lung tissues progress. CT scanning also helps determine the size of a contusion, which is useful in determining whether a patient needs mechanical ventilation; a larger volume of contused lung on CT scan is associated with an increased likelihood that ventilation will be needed. CT scans also help differentiate between contusion and pulmonary hematoma, which may be difficult to tell apart otherwise. However, pulmonary contusions that are visible on CT but not chest X-ray are usually not severe enough to affect outcome or treatment.

As with other chest injuries such as pulmonary contusion, hemothorax, and pneumothorax, pulmonary laceration can often be treated with just supplemental oxygen, ventilation, and drainage of fluids from the chest cavity. A thoracostomy tube can be used to remove blood and air from the chest cavity. About 5% of cases require surgery, called thoracotomy. Thoracotomy is especially likely to be needed if a lung fails to re-expand; if pneumothorax, bleeding, or coughing up blood persist; or in order to remove clotted blood from a hemothorax. Surgical treatment includes suturing, stapling, oversewing, and wedging out of the laceration. Occasionally, surgeons must perform a lobectomy, in which a lobe of the lung is removed, or a pneumonectomy, in which an entire lung is removed.

Pulmonary laceration may not be visible using chest X-ray because an associated pulmonary contusion or hemorrhage may mask it. As the lung contusion clears (usually within two to four days), lacerations begin to become visible on chest X-ray. CT scanning is more sensitive and better at detecting pulmonary laceration than X-rays are, and often reveals multiple lacerations in cases where chest X-ray showed only a contusion. Before CT scanning was widely available, pulmonary laceration was considered unusual because it was not common to find with X-ray alone. On a CT scan, pulmonary lacerations show up in a contused area of the lung, typically appearing as cavities filled with air or fluid that usually have a round or ovoid shape due to the lung's elasticity.

Hematomas appear on chest radiographs as smooth masses that are round or ovoid in shape. Like lacerations, hematomas may initially be hidden on X-ray by lung contusions, but they become more apparent as the contusion begins to heal. Pneumatoceles have a similar shape to that of hematomas but have thin, smooth walls. Lacerations may be filled completely with blood, completely with air, or partially with both. Lacerations filled with both blood and air display a distinctive air-fluid level. A single laceration may occur by itself, or many may be present, creating an appearance like Swiss cheese in the radiography of the lung.

Pulmonary laceration is usually accompanied by hemoptysis (coughing up blood or of blood-stained sputum).

Thoracoscopy may be used in both diagnosis and treatment of pulmonary laceration.

A healing laceration may resemble a pulmonary nodule on radiographs, but unlike pulmonary nodules, lacerations decrease in size over time on radiographs.

Diagnosis is by medical imaging with either plain X ray or CT scan.

Pulmonary aspiration resulting in pneumonia, in some patients, particularly those with physical limitations, can be fatal.

The prevalence of pulmonary interstitial emphysema widely varies with the population studied. In a 1987 study 3% of infants admitted to the neonatal intensive care unit (NICU) developed pulmonary interstitial emphysema.

There is no one single test for confirming that breathlessness is caused by pulmonary edema; indeed, in many cases, the cause of shortness of breath is probably multifactorial.

Low oxygen saturation and disturbed arterial blood gas readings support the proposed diagnosis by suggesting a pulmonary shunt. Chest X-ray will show fluid in the alveolar walls, Kerley B lines, increased vascular shadowing in a classical batwing peri-hilum pattern, upper lobe diversion (increased blood flow to the superior parts of the lung), and possibly pleural effusions. In contrast, patchy alveolar infiltrates are more typically associated with noncardiogenic edema

Lung ultrasound, employed by a healthcare provider at the point of care, is also a useful tool to diagnose pulmonary edema; not only is it accurate, but it may quantify the degree of lung water, track changes over time, and differentiate between cardiogenic and non-cardiogenic edema.

Especially in the case of cardiogenic pulmonary edema, urgent echocardiography may strengthen the diagnosis by demonstrating impaired left ventricular function, high central venous pressures and high pulmonary artery pressures.

Blood tests are performed for electrolytes (sodium, potassium) and markers of renal function (creatinine, urea). Liver enzymes, inflammatory markers (usually C-reactive protein) and a complete blood count as well as coagulation studies (PT, aPTT) are also typically requested. B-type natriuretic peptide (BNP) is available in many hospitals, sometimes even as a point-of-care test. Low levels of BNP (<100 pg/ml) suggest a cardiac cause is unlikely.

The PESI and sPESI scoring tools can estimate mortality of patients. The Geneva prediction rules and Wells criteria are used to calculate a pre-test probability of patients to predict who has a pulmonary embolism. These scores are tools to be used with clinical judgment in deciding diagnostic testing and types of therapy. The PESI algorithm comprises 11 routinely available clinical variables. It puts the subjects into one of five classes (I-V), with 30-day mortality ranging from 1.1% to 24.5%. Those in classes I and II are low-risk and those in classes III-V are high-risk.

Pulmonary interstitial emphysema often resolves gradually and may take 2–3 weeks. For longer durations of PIE the length of time of mechanical ventilation needed may increase and the incidence of bronchopulmonary dysplasia becomes higher. Some infants may develop chronic lobar emphysema, which may require surgical lobectomies.

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

The lungs are normally protected against aspiration by a series of "protective reflexes" such as coughing and swallowing. Significant aspiration can only occur if the protective reflexes are absent or severely diminished (in neurological disease, coma, drug overdose, sedation or general anesthesia). In intensive care, sitting patients up reduces the risk of pulmonary aspiration and ventilator-associated pneumonia.

Measures to prevent aspiration depend on the situation and the patient. In patients at imminent risk of aspiration, tracheal intubation by a trained health professional provides the best protection. A simpler intervention that can be implemented is to lay the patient on their side in the recovery position (as taught in first aid and CPR classes), so that any vomitus produced by the patient will drain out their mouth instead of back down their pharynx. Some anesthetists will use sodium citrate to neutralize the stomach's low pH and metoclopramide or domperidone (pro-kinetic agents) to empty the stomach.

People with chronic neurological disorders, for example, after a stroke, are less likely to aspirate thickened fluids.

The location of abscesses caused by aspiration depends on the position one is in. If one is sitting or standing up, the aspirate ends up in the posterior basal segment of the right lower lobe. If one is on one's back, it goes to the superior segment of the right lower lobe. If one is lying on the right side, it goes to the posterior segment of the right upper lobe, or the posterior basal segment of the right upper lobe. If one is lying on the left, it goes to the lingula.

Management has generally been reported to be conservative, though deaths have been reported.

- Removal from water

- Observation

- Diuretics and / or Oxygen when necessary

- Episodes are generally self-limiting in the absence of other medical problems

CT pulmonary angiography (CTPA) is a pulmonary angiogram obtained using computed tomography (CT) with radiocontrast rather than right heart catheterization. Its advantages are clinical equivalence, its non-invasive nature, its greater availability to people, and the possibility of identifying other lung disorders from the differential diagnosis in case there is no pulmonary embolism.

Assessing the accuracy of CT pulmonary angiography is hindered by the rapid changes in the number of rows of detectors available in multidetector CT (MDCT) machines. According to a cohort study, single-slice spiral CT may help diagnose detection among people with suspected pulmonary embolism. In this study, the sensitivity was 69% and specificity was 84%. In this study which had a prevalence of detection was 32%, the positive predictive value of 67.0% and negative predictive value of 85.2%. However, this study's results may be biased due to possible incorporation bias, since the CT scan was the final diagnostic tool in people with pulmonary embolism. The authors noted that a negative single slice CT scan is insufficient to rule out pulmonary embolism on its own. A separate study with a mixture of 4 slice and 16 slice scanners reported a sensitivity of 83% and a specificity of 96%, which means that it is a good test for ruling out a pulmonary embolism if it is not seen on imaging and that it is very good at confirming a pulmonary embolism is present if it is seen. This study noted that additional testing is necessary when the clinical probability is inconsistent with the imaging results. CTPA is non-inferior to VQ scanning, and identifies more emboli (without necessarily improving the outcome) compared to VQ scanning.

In those with underlying heart disease, effective control of congestive symptoms prevents pulmonary edema.

Dexamethasone is in widespread use for the prevention of high altitude pulmonary edema. Sildenafil is used as a preventive treatment for altitude-induced pulmonary edema and pulmonary hypertension, the mechanism of action is via phosphodiesterase inhibition which raises cGMP, resulting in pulmonary arterial vasodilation and inhibition of smooth muscle cell proliferation. While this effect has only recently been discovered, sildenafil is already becoming an accepted treatment for this condition, in particular in situations where the standard treatment of rapid descent has been delayed for some reason.

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.

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

The incidence of clinical HAPE in unacclimatized travelers exposed to high altitude (~) appears to be less than 1%. The U.S. Army Pike's Peak Research Laboratory has exposed sea-level-resident volunteers rapidly and directly to high altitude; during 30 years of research involving about 300 volunteers (and over 100 staff members), only three have been evacuated with suspected HAPE.

The death rate of people with flail chest depends on the severity of their condition, ranging from 10 to 25%.

SIPE is estimated to occur in 1-2% of competitive open-water swimmers, with 1.4% of triathletes, 1.8% of combat swimmers and 1.1% of divers and swimmers reported in the literature.

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.

Chest radiography is usually the first test to detect interstitial lung diseases, but the chest radiograph can be normal in up to 10% of patients, especially early on the disease process.

High resolution CT of the chest is the preferred modality, and differs from routine CT of the chest. Conventional (regular) CT chest examines 7–10 mm slices obtained

at 10 mm intervals; high resolution CT examines 1-1.5 mm slices at 10 mm

intervals using a high spatial frequency reconstruction algorithm. The HRCT therefore provides approximately 10 times more resolution than the conventional CT chest, allowing the HRCT to elicit details that cannot otherwise be visualized.

Radiologic appearance alone however is not adequate and should be interpreted in the clinical context, keeping in mind the temporal profile of the disease process.

Interstitial lung diseases can be classified according to radiologic patterns.

Clinically, IPH manifests as a triad of haemoptysis, diffuse parenchymal infiltrates on chest radiographs, and iron deficiency anaemia. It is diagnosed at an average age of 4.5 plus or minus 3.5 years, and it is twice as common in females. The clinical course of IPH is exceedingly variable, and most of the patients continue to have episodes of pulmonary haemorrhage despite therapy. Death may occur suddenly from acute pulmonary haemorrhage or after progressive pulmonary insufficiency resulting in chronic respiratory failure.

The standard and most important treatment is to descend to a lower altitude as quickly as possible, preferably by at least 1000 metres. Oxygen should also be given if possible. Symptoms tend to quickly improve with descent, but more severe symptoms may continue for several days. The standard drug treatments for which there is strong clinical evidence are dexamethasone and nifedipine. Phosphodiesterase inhibitors such as sildenafil and tadalafil are also effective but may worsen the headache of mountain sickness.

Usually the sequestration is removed after birth via surgery. In most cases this surgery is safe and effective; the child will grow up to have normal lung function.

In a few instances, fetuses with sequestrations develop problematic fluid collections in the chest cavity. In these situations a Harrison catheter shunt can be used to drain the chest fluid into the amniotic fluid.

In rare instances where the fetus has a very large lesion, resuscitation after delivery can be dangerous. In these situations a specialized delivery for management of the airway compression can be planned called the EXIT procedure, or a fetal laser ablation procedure can be performed. During this minimally invasive fetal intervention, a small needle is inserted into the sequestration, and a laser fiber is targeted at the abnormal blood vessel going to the sequestration. The goal of the operation is to use laser energy to stop the blood flow to the sequestration, causing it to stop growing. Ideally, after the surgery, the sequestration steals less blood flow from the fetus, and the heart and lungs start growing more normally as the sequestration shrinks in size and the pleural effusion goes away.

The treatment for this is a wedge resection, segmentectomy, or lobectomy via a VATS procedure or thoracotomy.

Pulmonary sequestrations usually get their blood supply from the thoracic aorta.