Pulmonary fibrosis creates scar tissue. The scarring is permanent once it has developed. Slowing the progression and prevention depends on the underlying cause:

- Treatment options for idiopathic pulmonary fibrosis are very limited. Though research trials are ongoing, there is no evidence that any medications can significantly help this condition. Lung transplantation is the only therapeutic option available in severe cases. Since some types of lung fibrosis can respond to corticosteroids (such as prednisone) and/or other medications that suppress the body's immune system, these types of drugs are sometimes prescribed in an attempt to slow the processes that lead to fibrosis.

- Two pharmacological agents intended to prevent scarring in mild idiopathic fibrosis are pirfenidone, which reduced reductions in the 1-year rate of decline in FVC. Pirfenidone also reduced the decline in distances on the 6-minute walk test, but had no effect on respiratory symptoms. The second agent is nintedanib, which acts as antifibrotic, mediated through the inhibition of a variety of tyrosine kinase receptors (including platelet-derived growth factor, fibroblast growth factor, and vascular endothelial growth factor). A randomized clinical trial showed it reduced lung-function decline and acute exacerbations.

- Anti-inflammatory agents have only limited success in reducing the fibrotic progress. Some of the other types of fibrosis, such as non-specific interstitial pneumonia, may respond to immunosuppressive therapy such as corticosteroids. However, only a minority of patients respond to corticosteroids alone, so additional immunosuppressants, such as cyclophosphamide, azathioprine, methotrexate, penicillamine, and cyclosporine may be used. Colchicine has also been used with limited success. There are ongoing trials with newer drugs such as IFN-γ and mycophenolate mofetil..

- Hypersensitivity pneumonitis, a less severe form of pulmonary fibrosis, is prevented from becoming aggravated by avoiding contact with the causative material.

- Oxygen supplementation improves the quality of life and exercise capacity. Lung transplantation may be considered for some patients.

"N"-Acetylcysteine (NAC) is a precursor to glutathione, an antioxidant. It has been hypothesized that treatment with high doses of NAC may repair an oxidant–antioxidant imbalance that occurs in the lung tissue of patients with IPF. In the first clinical trial of 180 patients (IFIGENIA), NAC was shown in previous study to reduce the decline in VC and DLCO over 12 months of follow-up when used in combination with prednisone and azathioprine (triple therapy).

More recently, a large randomized, controlled trial (PANTHER-IPF) was undertaken by the National Institutes of Health (NIH) in the USA to evaluate triple therapy and NAC monotherapy in IPF patients. This study found that the combination of prednisone, azathioprine, and NAC increased the risk of death and hospitalizations and the NIH announced in 2012 that the triple-therapy arm of the PANTHER-IPF study had been terminated early.

This study also evaluated NAC alone and the results for this arm of the study were published in May 2014 in the New England Journal of Medicine, concluding that "as compared with placebo, acetylcysteine offered no significant benefit with respect to the preservation of FVC in patients with idiopathic pulmonary fibrosis with mild-to-moderate impairment in lung function".

A Cochrane review comparing pirfenidone with placebo, found a reduced risk of disease progression by 30%. FVC or VC was also improved, even if a mild slowing in FVC decline could be demonstrated only in one of the two CAPACITY trials. A third study, which was completed in 2014 found reduced decline in lung function and IPF disease progression. The data from the ASCEND study were also pooled with data from the two CAPACITY studies in a pre-specified analysis which showed that pirfenidone reduced the risk of death by almost 50% over one year of treatment.

The dual (ET and ET) endothelin receptor antagonist bosentan was approved in 2001. Sitaxentan (Thelin) was approved for use in Canada, Australia, and the European Union, but not in the United States. In 2010, Pfizer withdrew Thelin worldwide because of fatal liver complications. A similar drug, ambrisentan is marketed as Letairis in the U.S. by Gilead Sciences.

The U.S. FDA approved sildenafil, a selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5), for the treatment of PAH in 2005. It is marketed for PAH as Revatio. In 2009, they also approved tadalafil, another PDE5 inhibitor, marketed under the name Adcirca. PDE5 inhibitors are believed to increase pulmonary artery vasodilation, and inhibit vascular remodeling, thus lowering pulmonary arterial pressure and pulmonary vascular resistance.

Tadalafil is taken orally, as well as sildenafil, and it is rapidly absorbed (serum levels are detectable at 20 minutes). The T (biological half-life) hovers around 17.5 hours in healthy subjects. Moreover, if we consider pharmacoeconomic implications, patients that take tadalafil would pay two-thirds of the cost of sildenafil therapy. However, there are some adverse effects of this drug such as headache, diarrhea, nausea, back pain, dyspepsia, flushing and myalgia.

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.

ILD is not a single disease, but encompasses many different pathological processes. Hence treatment is different for each disease.

If a specific occupational exposure cause is found, the person should avoid that environment. If a drug cause is suspected, that drug should be discontinued.

Many cases due to unknown or connective tissue-based causes are treated with corticosteroids, such as prednisolone. Some people respond to immunosuppressant treatment. Patients with a low level of oxygen in the blood may be given supplemental oxygen.

Pulmonary rehabilitation appears to be useful. Lung transplantation is an option if the ILD progresses despite therapy in appropriately selected patients with no other contraindications.

On October 16, 2014, the Food and Drug Administration approved a new drug for the treatment of Idiopathic Pulmonary Fibrosis (IPF). This drug, Ofev (nintedanib), is marketed by Boehringer Ingelheim Pharmaceuticals, Inc. This drug has been shown to slow the decline of lung function although the drug has not been shown to reduce mortality or improve lung function. The estimated cost of the drug per year is approximately $94,000.

To date, no treatment has been proven to effectively reverse or prevent the progression of PAM. Lung transplantation is an option for end stage disease, but is typically only recommended as a last resort when quality of life is significantly impaired.

Etidronate is a bisphosphonate and can reduce the formation of calcium hydroxyapatite crystals. It has led to clinical and radiological improvements in few cases.

Several mechanical techniques are used to dislodge sputum and encourage its expectoration. In the hospital setting, chest physiotherapy is used; a respiratory therapist percusses an individual's chest by hand several times a day, to loosen up secretions. Chest physiotherapy is beneficial for short-term airway clearance. Devices that recreate this percussive therapy include the ThAIRapy Vest and the intrapulmonary percussive ventilator. Other methods such as biphasic cuirass ventilation, and associated clearance mode available in such devices, integrate a cough assistance phase, as well as a vibration phase for dislodging secretions. These are portable and adapted for home use.

Ivacaftor is a medication taken by mouth for the treatment of CF due to a number of specific mutations. It improves lung function by about 10%; however, as of 2014 it is expensive.

Aerosolized medications that help loosen secretions include dornase alfa and hypertonic saline. Dornase is a recombinant human deoxyribonuclease, which breaks down DNA in the sputum, thus decreasing its viscosity. Denufosol, an investigational drug, opens an alternative chloride channel, helping to liquefy mucus. Whether inhaled corticosteroids are useful is unclear, but stopping inhaled corticosteroid therapy is safe. There is weak evidence that corticosteroid treatment may cause harm by interfering with growth.

As lung disease worsens, mechanical breathing support may become necessary. Individuals with CF may need to wear special masks at night to help push air into their lungs. These machines, known as bilevel positive airway pressure (BiPAP) ventilators, help prevent low blood oxygen levels during sleep. Non-invasive ventilators may be used during physical therapy to improve sputum clearance. It is not known if this type of therapy has an impact on pulmonary exacerbations or disease progression. It is not known what role non-invasive ventilation therapy has for improving exercise capacity in people with cystic fibrosis. During severe illness, a tube may be placed in the throat (a procedure known as a tracheostomy) to enable breathing supported by a ventilator.

For children, preliminary studies show massage therapy may help people and their families' quality of life. Pneumococcal vaccination has not been studied as of 2014.

Some lung infections require surgical removal of the infected part of the lung. If this is necessary many times, lung function is severely reduced.

Within all classes of medicinal drugs that possibly can lead to pulmonary toxicity as a side effect, most pulmonary toxicity is due to chemotherapy for cancer.

Many medicinal drugs can lead to pulmonary toxicity. A few medicinal drugs can lead to pulmonary toxicity frequently (in medicine defined by international regulatory authorities such as the U.S. Food and Drug Administration and the EMEA [European Union] as > 1% and 10%). These medicinal drugs can include gold and nitrofurantoin, as well as the following drugs used in chemotherapy for cancer: Methotrexate, the taxanes (paclitaxel and docetaxel), gemcitabine, bleomycin, mitomycin C, busulfan, cyclophosphamide, chlorambucil, and nitrosourea (e.g., carmustine).

Also, some medicinal drugs used in cardiovascular medicine can lead to pulmonary toxicity frequently or very frequently. These include above all amiodarone, as well as beta blockers, ACE inhibitors (however, pulmonary toxicity of ACE inhibitors usually lasts only 3–4 months and then usually disappears by itself), procainamide, quinidine, tocainide, and minoxidil.

Both oncologists and cardiologists are well aware of possible pulmonary toxicity.

Many people with CF are on one or more antibiotics at all times, even when healthy, to prophylactically suppress infection. Antibiotics are absolutely necessary whenever pneumonia is suspected or a noticeable decline in lung function is seen, and are usually chosen based on the results of a sputum analysis and the person's past response. This prolonged therapy often necessitates hospitalization and insertion of a more permanent IV such as a peripherally inserted central catheter or Port-a-Cath. Inhaled therapy with antibiotics such as tobramycin, colistin, and aztreonam is often given for months at a time to improve lung function by impeding the growth of colonized bacteria. Inhaled antibiotic therapy helps lung function by fighting infection, but also has significant drawbacks such as development of antibiotic resistance, tinnitus, and changes in the voice. Inhaled levofloxacin may be used to treat "Pseudomonas aeruginosa" in people with cystic fibrosis who are infected.

Antibiotics by mouth such as ciprofloxacin or azithromycin are given to help prevent infection or to control ongoing infection. The aminoglycoside antibiotics (e.g. tobramycin) used can cause hearing loss, damage to the balance system in the inner ear or kidney failure with long-term use. To prevent these side-effects, the amount of antibiotics in the blood is routinely measured and adjusted accordingly.

Radiation (radiotherapy) is frequently used for the treatment of many cancer types, and can be highly effective. Unfortunately, it also can lead to pulmonary toxicity as a side effect.

Radiotherapists are well aware of possible pulmonary toxicity, and take a number of precautions to minimise the incidence of this side effect. There are research efforts to possibly eliminate this side effect in the future.

There is no standardized treatment for indium lung disease. Treatment options include pulmonary lavage and corticosteroid therapy. Prognostic factors were a matter of research as of 2012, but preliminary evidence suggests that duration of employment and reported use of respiratory protection are not prognostic factors, but the serum level of indium may be a prognostic factor - higher levels of serum indium have been associated with worse prognoses. Indium lung disease has been fatal in several cases.

Lung cancer may be related to indium lung disease, though indium is not a known carcinogen.

Therapeutic interventions with medium-chain triglyceride-enriched low-fat diets, intratracheal heparin, inhaled tissue plasminogen activator, and steroids have also been reported and have met with variable success.

Inhaled mucolytics: Potassium iodide and acetylcysteine inhaled therapy are often used to help the patient cough up the casts by breaking down the thick mucus formations.

Inhaled and oral steroids: If PB is associated with asthma or an infection, inhaled and oral steroids have been shown to be effective.

Treatment is directed at correcting the underlying cause. Post-surgical atelectasis is treated by physiotherapy, focusing on deep breathing and encouraging coughing. An incentive spirometer is often used as part of the breathing exercises. Walking is also highly encouraged to improve lung inflation. People with chest deformities or neurologic conditions that cause shallow breathing for long periods may benefit from mechanical devices that assist their breathing. One method is continuous positive airway pressure, which delivers pressurized air or oxygen through a nose or face mask to help ensure that the alveoli do not collapse, even at the end of a breath. This is helpful, as partially inflated alveoli can be expanded more easily than collapsed alveoli. Sometimes additional respiratory support is needed with a mechanical ventilator.

The primary treatment for acute massive atelectasis is correction of the underlying cause. A blockage that cannot be removed by coughing or by suctioning the airways often can be removed by bronchoscopy. Antibiotics are given for an infection. Chronic atelectasis is often treated with antibiotics because infection is almost inevitable. In certain cases, the affected part of the lung may be surgically removed when recurring or chronic infections become disabling or bleeding is significant. If a tumor is blocking the airway, relieving the obstruction by surgery, radiation therapy, chemotherapy, or laser therapy may prevent atelectasis from progressing and recurrent obstructive pneumonia from developing.

Acute therapy for PB is often focused on removal or facilitated expectoration of the casts. This is followed by short and long term efforts to identify and remediate the underlying condition resulting in the excessive airway leakage or inflammation that is causing the casts to form.

PB can present as a life threatening emergency when the casts obstruct the major airways resulting in acute respiratory distress. Intervention by a skilled physician experienced with foreign body removal from the lungs is essential. Evaluation by means of bronchoscopy can be difficult and time consuming and is best performed under general anesthesia.

Casts can be removed mechanically by bronchoscopy or physical therapy. High-frequency chest wall oscillation can also be used to vibrate the chest wall at a high frequency to try to loosen and thin the casts. Inhaled therapy using bronchodilators, corticosteroids or mucolytics can be used to try to disrupt the cast formation.

Recently, heavy T2-weighted MRI has revealed that occult lymphatic anomalies that represent developmental remnants or subclinical GLA are present in adults who present with expectoration of large multiantennary, branching casts. Intranodal lymphangiogram and dynamic contrast-enhanced MR lymphangiography have been used to more precisely image the leaks, and in the small number of patients who have been treated to date, embolization of the TD has been highly successful in controlling cast formation.

Cannulation of the thoracic duct followed by embolization should be considered in those patients who are shown to have leakage of lymphatic fluid into the airway.

The National Institute of Occupational Safety and Health, Japan (JNIOSH) set limits for acceptable exposure at 0.0003 mg/m after the discovery of indium lung. Methods for reducing indium exposure are thought to be the best mode of protection. Medical surveillance of indium workers is also a method of prevention.

Many people with this condition have no symptoms. Treatment is aimed at the health problems causing the lung problem and the complications caused by the disorder.

Fast-acting drugs for RA include aspirin and corticosteroids, which alleviate pain and reduce inflammation. Slow-acting drugs termed disease modifying antirheumatic drugs (DMARDs), include gold, methotrexate and hydroxychloroquine (Plaquenil), which promote disease remission and prevent progressive joint destruction. In patients with less severe RA, pain relievers, anti-inflammatory drugs and physical rest are sufficient to improve quality of life. In patients with joint deformity, surgery is the only alternative for recovering articular function.

Prognosis is related to the underlying disorder and the type and severity of lung disease. In severe cases, lung transplantation can be considered. This is more common in cases of bronchiolitis obliterans, pulmonary fibrosis, or pulmonary hypertension. Most complications are not fatal, but does reduce life expectancy to an estimated 5 to 10 years.

Treatment depends on the underlying cause. Treatments include iced saline, and topical vasoconstrictors such as adrenalin or vasopressin. Selective bronchial intubation can be used to collapse the lung that is bleeding. Also, endobronchial tamponade can be used. Laser photocoagulation can be used to stop bleeding during bronchoscopy. Angiography of bronchial arteries can be performed to locate the bleeding, and it can often be embolized. Surgical option is usually the last resort, and can involve, removal of a lung lobe or removal of the entire lung. Non–small-cell lung cancer can also be treated with erlotinib or gefitinib. Cough suppressants can increase the risk of choking.

Underlying disease must be controlled to prevent exacerbation and worsening of ABPA, and in most patients this consists of managing their asthma or CF. Any other co-morbidities, such as sinusitis or rhinitis, should also be addressed.

Hypersensitivity mechanisms, as described above, contribute to progression of the disease over time and, when left untreated, result in extensive fibrosis of lung tissue. In order to reduce this, corticosteroid therapy is the mainstay of treatment (for example with prednisone); however, studies involving corticosteroids in ABPA are limited by small cohorts and are often not double-blinded. Despite this, there is evidence that acute-onset ABPA is improved by corticosteroid treatment as it reduces episodes of consolidation. There are challenges involved in long-term therapy with corticosteroids—which can induce severe immune dysfunction when used chronically, as well as metabolic disorders—and approaches have been developed to manage ABPA alongside potential adverse effects from corticosteroids.

The most commonly described technique, known as sparing, involves using an antifungal agent to clear spores from airways adjacent to corticosteroid therapy. The antifungal aspect aims to reduce fungal causes of bronchial inflammation, whilst also minimising the dose of corticosteroid required to reduce the immune system’s input to disease progression. The strongest evidence (double-blinded, randomized, placebo-controlled trials) is for itraconazole twice daily for four months, which resulted in significant clinical improvement compared to placebo, and was mirrored in CF patients. Using itraconazole appears to outweigh the risk from long-term and high-dose prednisone. Newer triazole drugs—such as posaconazole or voriconazole—have not yet been studied in-depth through clinical trials in this context.

Whilst the benefits of using corticosteroids in the short term are notable, and improve quality of life scores, there are cases of ABPA converting to invasive aspergillosis whilst undergoing corticosteroid treatment. Furthermore, in concurrent use with itraconazole, there is potential for drug interaction and the induction of Cushing syndrome in rare instances. Metabolic disorders, such as diabetes mellitus and osteoporosis, can also be induced.

In order to mitigate these risks, corticosteroid doses are decreased biweekly assuming no further progression of disease after each reduction. When no exacerbations from the disease are seen within three months after discontinuing corticosteroids, the patient is considered to be in complete remission. The exception to this rule is patients who are diagnosed with advanced ABPA; in this case removing corticosteroids almost always results in exacerbation and these patients are continued on low-dose corticosteroids (preferably on an alternate-day schedule).

Serum IgE can be used to guide treatment, and levels are checked every 6–8 week after steroid treatment commences, followed by every 8 weeks for one year. This allows for determination of baseline IgE levels, though it’s important to note that most patients do not entirely reduce IgE levels to baseline. Chest X-ray or CT scans are performed after 1–2 months of treatment to ensure infiltrates are resolving.

There is evidence to show that steroids given to babies less than 8 days old can prevent bronchopulmonary dysplasia. However, the risks of treatment may outweigh the benefits.

It is unclear if starting steroids more than 7 days after birth is harmful or beneficial. It is thus recommended that they only be used in those who cannot be taken off of a ventilator.

Patients with single aspergillomas generally do well with surgery to remove the aspergilloma, and are best given pre-and post-operative antifungal drugs. Often, no treatment is necessary. However, if a patient coughs up blood (haemoptysis), treatment may be required (usually angiography and embolisation, surgery or taking tranexamic acid). Angiography (injection of dye into the blood vessels) may be used to find the site of bleeding which may be stopped by shooting tiny pellets into the bleeding vessel.

For chronic cavitary pulmonary aspergillosis and chronic fibrosing pulmonary aspergillosis, lifelong use of antifungal drugs is usual. Itraconazole and voriconazole are first and second-line anti fungal agents respectively. Posaconazole can be used as third-line agent, for patients who are intolerant of or developed resistance to the first and second-line agents. Regular chest X-rays, serological and mycological parameters as well as quality of life questionnaires are used to monitor treatment progress. It is important to monitor the blood levels of antifungals to ensure optimal dosing as individuals vary in their absorption levels of these drugs.

Treatment of bronchiectasis includes controlling infections and bronchial secretions, relieving airway obstructions, removal of affected portions of lung by surgical removal or artery embolization and preventing complications. The prolonged use of antibiotics prevents detrimental infections and decreases hospitalizations in people with bronchiectasis, but also increases the risk of people becoming infected with drug-resistant bacteria.

Other treatment options include eliminating accumulated fluid with postural drainage and chest physiotherapy. Postural drainage techniques, aided by physiotherapists and respiratory therapists, are an important mainstay of treatment. Airway clearance techniques appear useful.

Surgery may also be used to treat localized bronchiectasis, removing obstructions that could cause progression of the disease.

Inhaled steroid therapy that is consistently adhered to can reduce sputum production and decrease airway constriction over a period of time, and help prevent progression of bronchiectasis. This is not recommended for routine use in children. One commonly used therapy is beclometasone dipropionate.

Although not approved for use in any country, mannitol dry inhalation powder, has been granted orphan drug status by the FDA for use in people with bronchiectasis and with cystic fibrosis.

Specific pretreatments, drugs to prevent chemically induced lung injuries due to respiratory airway toxins, are not available. Analgesic medications, oxygen, humidification, and ventilator support currently constitute standard therapy. In fact, mechanical ventilation remains the therapeutic mainstay for acute inhalation injury. The cornerstone of treatment is to keep the PaO2 > 60 mmHg (8.0 kPa), without causing injury to the lungs with excessive O2 or volutrauma. Pressure control ventilation is more versatile than volume control, although breaths should be volume limited, to prevent stretch injury to the alveoli. Positive end-expiratory pressure (PEEP) is used in mechanically ventilated patients with ARDS to improve oxygenation. Hemorrhaging, signifying substantial damage to the lining of the airways and lungs, can occur with exposure to highly corrosive chemicals and may require additional medical interventions. Corticosteroids are sometimes administered, and bronchodilators to treat bronchospasms. Drugs that reduce the inflammatory response, promote healing of tissues, and prevent the onset of pulmonary edema or secondary inflammation may be used following severe injury to prevent chronic scarring and airway narrowing.

Although current treatments can be administered in a controlled hospital setting, many hospitals are ill-suited for a situation involving mass casualties among civilians. Inexpensive positive-pressure devices that can be used easily in a mass casualty situation, and drugs to prevent inflammation and pulmonary edema are needed. Several drugs that have been approved by the FDA for other indications hold promise for treating chemically induced pulmonary edema. These include β2-agonists, dopamine, insulin, allopurinol, and non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. Ibuprofen is particularly appealing because it has an established safety record and can be easily administered as an initial intervention. Inhaled and systemic forms of β2-agonists used in the treatment of asthma and other commonly used medications, such as insulin, dopamine, and allopurinol have also been effective in reducing pulmonary edema in animal models but require further study. A recent study documented in the "AANA Journal" discussed the use of volatile anesthetic agents, such as sevoflurane, to be used as a bronchodilator that lowered peak airway pressures and improved oxygenation. Other promising drugs in earlier stages of development act at various steps in the complex molecular pathways underlying pulmonary edema. Some of these potential drugs target the inflammatory response or the specific site(s) of injury. Others modulate the activity of ion channels that control fluid transport across lung membranes or target surfactant, a substance that lines the air sacs in the lungs and prevents them from collapsing. Mechanistic information based on toxicology, biochemistry, and physiology may be instrumental in determining new targets for therapy. Mechanistic studies may also aid in the development of new diagnostic approaches. Some chemicals generate metabolic byproducts that could be used for diagnosis, but detection of these byproducts may not be possible until many hours after initial exposure. Additional research must be directed at developing sensitive and specific tests to identify individuals quickly after they have been exposed to varying levels of chemicals toxic to the respiratory tract.

Currently there are no clinically approved agents that can reduce pulmonary and airway cell dropout and avert the transition to pulmonary and /or airway fibrosis.

Treatment is primarily supportive. Management in an intensive care unit is required and the need for mechanical ventilation is common. Therapy with corticosteroids is generally attempted, though their usefulness has not been established. The only treatment that has met with success to date is a lung transplant.