Tuberculosis, pneumonia, inhaled foreign bodies, allergic bronchopulmonary aspergillosis and bronchial tumours are the major acquired causes of bronchiectasis. Infective causes associated with bronchiectasis include infections caused by the Staphylococcus, Klebsiella, or Bordetella pertussis, the causative agent of whooping cough and nontuberculous mycobacteria.

Aspiration of ammonia and other toxic gases, pulmonary aspiration, alcoholism, heroin (drug use), various allergies all appear to be linked to the development of bronchiectasis.

Various immunological and lifestyle factors have also been linked to the development of bronchiectasis:

- Childhood Acquired Immune Deficiency Syndrome (AIDS), which predisposes patients to a variety of pulmonary ailments, such as pneumonia and other opportunistic infections.

- Inflammatory bowel disease, especially ulcerative colitis. It can occur in Crohn's disease as well, but does so less frequently. Bronchiectasis in this situation usually stems from various allergic responses to inhaled fungal spores. A Hiatal hernia can cause Bronchiectasis when the stomach acid that is aspirated into the lungs causes tissue damage.

- People with rheumatoid arthritis who smoke appear to have a tenfold increased rate of the disease. Still, it is unclear as to whether or not cigarette smoke is a specific primary cause of bronchiectasis.

- Case reports of Hashimoto's thyroiditis and bronchiectasis occurring in the same persons have been published.

No cause is identified in up to 50% of non-cystic-fibrosis related bronchiectasis.

According to a recent study, the main risk factors for RA-ILD are advancing age, male sex, greater RA disease activity, rheumatoid factor (RF) positivity, and elevated titers of anticitrullinated protein antibodies such as anticyclic citrullinated peptide. Cigarette smoking also appears to increase risk of RA-ILD, especially in patients with human leukocyte antigen DRB1.

A recently published retrospective study by a team from Beijing Chao-Yang Hospital in Beijing, China, supported three of the risk factors listed for RA-ILD and identified an additional risk factor. In that study of 550 RA patients, logistic regression analysis of data collected on the 237 (43%) with ILD revealed that age, smoking, RF positivity, and elevated lactate dehydrogenase closely correlated with ILD.

Recent studies have identified risk factors for disease progression and mortality. A retrospective study of 167 patients with RA-ILD determined that the usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography (HRCT) was a risk factor for progression, as were severe disease upon diagnosis and rate of change in pulmonary function test results in the first 6 months after diagnosis.

A study of 59 RA-ILD patients found no median survival difference between those with the UIP pattern and those without it. But the UIP group had more deaths, hospital admissions, need for supplemental oxygen, and decline in lung function.

In order to prevent bronchiectasis, children should be immunized against measles, pertussis, pneumonia, and other acute respiratory infections of childhood. While smoking has not been found to be a direct cause of bronchiectasis, it is certainly an irritant that all patients should avoid in order to prevent the development of infections (such as bronchitis) and further complications.

Treatments to slow down the progression of this chronic disease include keeping bronchial airways clear and secretions weakened through various forms of pneumotherapy. Aggressively treating bronchial infections with antibiotics to prevent the destructive cycle of infection, damage to bronchial tubes, and more infection is also standard treatment. Regular vaccination against pneumonia, influenza and pertussis are generally advised. A healthy body mass index and regular doctor visits may have beneficial effects on the prevention of progressing bronchiectasis. The presence of hypoxemia, hypercapnia, dyspnea level and radiographic extent can greatly affect the mortality rate from this disease.

If left untreated, miliary tuberculosis is almost always fatal. Although most cases of miliary tuberculosis are treatable, the mortality rate among children with miliary tuberculosis remains 15 to 20% and for adults 25 to 30%. One of the main causes for these high mortality rates includes late detection of disease caused by non-specific symptoms. Non-specific symptoms include: coughing, weight loss, or organ dysfunction. These symptoms may be implicated in numerous disorders, thus delaying diagnosis. Misdiagnosis with tuberculosis meningitis is also a common occurrence when patients are tested for tuberculosis, since the two forms of tuberculosis have high rates of co-occurrence.

A number of factors make people more susceptible to TB infections. The most important risk factor globally is HIV; 13% of all people with TB are infected by the virus. This is a particular problem in sub-Saharan Africa, where rates of HIV are high. Of people without HIV who are infected with tuberculosis, about 5–10% develop active disease during their lifetimes; in contrast, 30% of those coinfected with HIV develop the active disease.

Tuberculosis is closely linked to both overcrowding and malnutrition, making it one of the principal diseases of poverty. Those at high risk thus include: people who inject illicit drugs, inhabitants and employees of locales where vulnerable people gather (e.g. prisons and homeless shelters), medically underprivileged and resource-poor communities, high-risk ethnic minorities, children in close contact with high-risk category patients, and health-care providers serving these patients.

Chronic lung disease is another significant risk factor. Silicosis increases the risk about 30-fold. Those who smoke cigarettes have nearly twice the risk of TB compared to nonsmokers.

Other disease states can also increase the risk of developing tuberculosis. These include alcoholism and diabetes mellitus (three-fold increase).

Certain medications, such as corticosteroids and infliximab (an anti-αTNF monoclonal antibody), are becoming increasingly important risk factors, especially in the developed world.

Genetic susceptibility also exists, for which the overall importance remains undefined.

Progression from TB infection to overt TB disease occurs when the bacilli overcome the immune system defenses and begin to multiply. In primary TB disease (some 1–5% of cases), this occurs soon after the initial infection. However, in the majority of cases, a latent infection occurs with no obvious symptoms. These dormant bacilli produce active tuberculosis in 5–10% of these latent cases, often many years after infection.

The risk of reactivation increases with immunosuppression, such as that caused by infection with HIV. In people coinfected with "M. tuberculosis" and HIV, the risk of reactivation increases to 10% per year. Studies using DNA fingerprinting of "M. tuberculosis" strains have shown reinfection contributes more substantially to recurrent TB than previously thought, with estimates that it might account for more than 50% of reactivated cases in areas where TB is common. The chance of death from a case of tuberculosis is about 4% as of 2008, down from 8% in 1995.

Patients with miliary tuberculosis often experience non-specific signs, such as coughing and enlarged lymph nodes. Miliary tuberculosis can also present with enlarged liver (40% of cases), enlarged spleen (15%), inflammation of the pancreas (<5%), and multiple organ dysfunction with adrenal insufficiency (adrenal glands do not produce enough steroid hormones to regulate organ function). Miliary tuberculosis may also present with unilateral or bilateral pneumothorax rarely. Stool may also be diarrheal in nature and appearance.

Other symptoms include fever, hypercalcemia, chorodial tubercles and cutaneous lesions.

Firstly, many patients can experience a fever lasting several weeks with daily spikes in morning temperatures.

Secondly, hypercalcemia prevails in 16 to 51% of tuberculosis cases. It is thought that hypercalcemia occurs as a response to increased macrophage activity in the body. Such that, 1,25 dihydroxycholecalciferol (also referred to as calcitriol) improves the ability of macrophages to kill bacteria; however, higher levels of calcitriol lead to higher calcium levels, and thus hypercalcemia in some cases. Thus, hypercalcemia proves to be an important symptom of miliary tuberculosis.

Thirdly, chorodial tubercules, pale lesions on the optic nerve, typically indicate miliary tuberculosis in children. These lesions may occur in one eye or both; the number of lesions varies between patients. Chorodial tubercules may serve as important symptoms of miliary tuberculosis, since their presence can often confirm suspected diagnosis.

Lastly, between 10 and 30% of adults, and 20–40% of children with miliary tuberculosis have tuberculosis meningitis. This relationship results from myobacteria from miliary tuberculosis spreading to the brain and the subarachnoid space; as a result, leading to tuberculosis meningitis.

The risk factors for contracting miliary tuberculosis are being in direct contact with a person who has it, living in unsanitary conditions, and having an unhealthy diet. In the U.S., risk factors for contracting the disease include homelessness and HIV/AIDS.

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.

Tuberculous pericarditis is a form of pericarditis.

Pericarditis caused by tuberculosis is difficult to diagnose, because definitive diagnosis requires culturing "Mycobacterium tuberculosis" from aspirated pericardial fluid or pericardial , which requires high technical skill and is often not diagnostic (the yield from culture is low even with optimum specimens). The Tygerberg scoring system helps the clinician to decide whether pericarditis is due to tuberculosis or whether it is due to another cause: night sweats (1 point), weight loss (1 point), fever (2 point), serum globulin > 40g/l (3 points), blood total leucocyte count <10 x 10/l (3 points); a total score of 6 or more is highly suggestive of tuberculous pericarditis. Pericardial fluid with an interferon-γ level greater than 50/ml is highly specific for tuberculous pericarditis.

There are no randomized trials which evaluate the length of anti-tuberculosis treatment required for tuberculous pericarditis. There is a small but not conclusive benefit for treatment with a schedule of steroids with anti-tuberculosis drugs. Open surgical drainage of fluid though effective in preventing cardiac tamponade was associated with more deaths.

DPB has its highest prevalence among the Japanese, at 11 per 100,000 population. Korean, Chinese, and Thai individuals with the disease have been reported as well. A genetic predisposition among East Asians is suggested. The disease is more common in males, with the male to female ratio at 1.4–2:1 (or about 5 men to 3 women). The average onset of the disease is around age 40, and two-thirds of those affected are non-smokers, although smoking is not believed to be a cause. The presence of HLA-Bw54 increases the risk of diffuse panbronchiolitis 13.3-fold.

In Europe and the Americas, a relatively small number of DPB cases have been reported in Asian immigrants and residents, as well as in individuals of non-Asian ancestry. Misdiagnosis has occurred in the West owing to less recognition of the disease than in Asian countries. Relative to the large number of Asians living in the west, the small number of them thought to be affected by DPB suggests non-genetic factors may play some role in its cause. This rarity seen in Western Asians may also be partly associated with misdiagnosis.

In the post-antibiotic era pattern of frequency is changing. In older studies anaerobes were found in up to 90% cases but they are much less frequent now.

HIV-infected children less than 12 years of age also develop disseminated MAC. Some age adjustment is necessary when clinicians interpret CD4+ T-lymphocyte counts in children less than 2 years of age. Diagnosis, therapy, and prophylaxis should follow recommendations similar to those for adolescents and adults.

A parapneumonic effusion is a type of pleural effusion that arises as a result of a pneumonia, lung abscess, or bronchiectasis. There are three types of parapneumonic effusions: uncomplicated effusions, complicated effusions, and empyema. Uncomplicated effusions generally respond well to appropriate antibiotic treatment.

- Diagnosis

The criteria for a complicated parapneumonic effusion include the presence of pus, Gram stain–positive or culture-positive pleural fluid, pleural fluid pH <7.20, and pleural fluid LDH that is greater than three times the upper limit of normal of serum LDH. Diagnostic techniques available include plain film chest x-ray, computed tomography (CT), and ultrasound. Ultrasound can be useful in differentiating between empyema and other transudative and exudative effusions due in part to relative echogenicity of different organs such as the liver (often isoechogenic with empyema).

- Treatment

Appropriate management includes chest tube drainage (tube thoracostomy). Treatment of empyemas includes antibiotics, complete pleural fluid drainage, and reexpansion of the lung.

Other treatments include the use of decortication.

Conditions which commonly involve hemoptysis include bronchitis and pneumonia, lung cancers and tuberculosis. Other possible underlying causes include aspergilloma, bronchiectasis, coccidioidomycosis, pulmonary embolism, pneumonic plague, and cystic fibrosis. Rarer causes include hereditary hemorrhagic telangiectasia (HHT or Rendu-Osler-Weber syndrome), Goodpasture's syndrome, and granulomatosis with polyangiitis. In children, hemoptysis is commonly caused by the presence of a foreign body in the airway. The condition can also result from over-anticoagulation from treatment by drugs such as warfarin.

Blood-laced mucus from the sinus or nose area can sometimes be misidentified as symptomatic of hemoptysis (such secretions can be a sign of nasal or sinus cancer, but also a sinus infection). Extensive non-respiratory injury can also cause one to cough up blood. Cardiac causes like congestive heart failure and mitral stenosis should be ruled out.

The origin of blood can be identified by observing its color. Bright-red, foamy blood comes from the respiratory tract, whereas dark-red, coffee-colored blood comes from the gastrointestinal tract. Sometimes hemoptysis may be rust-colored.

The most common cause of minor hemoptysis is bronchitis.

- Lung cancer, including both non-small cell lung carcinoma and small cell lung carcinoma.

- Sarcoidosis

- Aspergilloma

- Tuberculosis

- Histoplasmosis

- Pneumonia

- Pulmonary edema

- Pulmonary embolism

- Foreign body aspiration and aspiration pneumonia

- Goodpasture's syndrome

- Granulomatosis with polyangiitis

- Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)

- Bronchitis

- Bronchiectasis

- Pulmonary embolism

- Anticoagulant use

- Trauma

- Lung abscess

- Mitral stenosis

- Tropical eosinophilia

- Bleeding disorders

- Hughes-Stovin Syndrome and other variants of Behçet's disease

- Squamous Cell Carcinoma Of Esophagus

Acute bronchitis is one of the most common diseases. About 5% of adults are affected and about 6% of children have at least one episode a year. It occurs more often in the winter. More than 10 million people in the United States visit a doctor each year for this condition with about 70% receiving antibiotics which are mostly not needed. There are efforts to decrease the use of antibiotics in acute bronchitis.

A study conducted on 452 patients revealed that the genotype responsible for higher IL-10 expression makes HIV infected people more susceptible to tuberculosis infection. Another study on HIV-TB co-infected patients also concluded that higher level of IL-10 and IL-22 makes TB patient more susceptible to Immune reconstitution inflammatory syndrome (IRIS). It is also seen that HIV co-infection with tuberculosis also reduces concentration of immunopathogenic matrix metalloproteinase (MMPs) leading to reduced inflammatory immunopathology.

Patients, families, and caregivers are encouraged to join the NIH Rare Lung Diseases Consortium Contact Registry. This is a privacy protected site that provides up-to-date information for individuals interested in the latest scientific news, trials, and treatments related to rare lung diseases.

Untreated DPB leads to bronchiectasis, respiratory failure, and death. A journal report from 1983 indicated that untreated DPB had a five-year survival rate of 62.1%, while the 10-year survival rate was 33.2%. With erythromycin treatment, individuals with DPB now have a much longer life expectancy due to better management of symptoms, delay of progression, and prevention of associated infections like "P. aeruginosa". The 10-year survival rate for treated DPB is about 90%. In DPB cases where treatment has resulted in significant improvement, which sometimes happens after about two years, treatment has been allowed to end for a while. However, individuals allowed to stop treatment during this time are closely monitored. As DPB has been proven to recur, erythromycin therapy must be promptly resumed once disease symptoms begin to reappear. In spite of the improved prognosis when treated, DPB currently has no known cure.

Most cases respond to antibiotics and prognosis is usually excellent unless there is a debilitating underlying condition. Mortality from lung abscess alone is around 5% and is improving.

Chronic bronchitis has a 3.4% to 22% prevalence rate among the general population. Individuals over the age of 45, smokers, those that live in areas with high air pollution and those have asthma have a higher risk of developing chronic bronchitis. This wide range is due to the different definitions of chronic bronchitis which can be defined based on signs and symptoms or the clinical diagnosis of the disorder. Chronic bronchitis tends to affect men more often than women. While the primary risk factor for chronic bronchitis is smoking, there is still a 4%-22% chance that people with chronic bronchitis were never smokers. This might suggest other risk factors such as the inhalation of fuels, dusts, and fumes. Obesity has also been linked to an increased risk in the onset of chronic bronchitis. In the United States in the year 2014 per 100,000 population the death rate of chronic bronchitis was 0.2%.

The most common organ affected by aspergilloma is the lung. Aspergilloma mainly affects people with underlying cavitary lung disease such as tuberculosis, sarcoidosis, bronchiectasis, cystic fibrosis and systemic immunodeficiency. "Aspergillus fumigatus", the most common causative species, is typically inhaled as small (2 to 3 micron) spores. The fungus settles in a cavity and is able to grow free from interference because critical elements of the immune system are unable to penetrate into the cavity. As the fungus multiplies, it forms a ball, which incorporates dead tissue from the surrounding lung, mucus, and other debris.

MAI is common in immunocompromised individuals, including senior citizens and those with HIV/AIDS or cystic fibrosis. Bronchiectasis, the bronchial condition which causes unnatural enlargement of the bronchial tubes, is commonly found with MAI infection. Whether the bronchiectasis leads to the MAC infection or is the result of it is not always known.

The "Mycobacterium avium complex" (MAC) includes common atypical bacteria, i.e. nontuberculous mycobacteria (NTM), found in the environment which can infect people with HIV and low CD4 cell count (below 100/microliter); mode of infection is usually inhalation or ingestion.

MAC causes disseminated disease in up to 40% of people with human immunodeficiency virus (HIV) in the United States, producing fever, sweats, weight loss, and anemia. Disseminated MAC characteristically affects people with advanced HIV disease and peripheral CD4+ T-lymphocyte counts less than 100 cells/uL. Effective prevention and therapy of MAC has the potential to contribute substantially to improved quality of life and duration of survival for HIV-infected persons.

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.

To date, about 420 cases have been reported in the medical literature. Given its unusual nature, the true prevalence of PB is unknown, and it is likely that many patients are undiagnosed. PB does affect patients of all age groups and both genders.

An aspergilloma, also known as a "mycetoma or fungus ball"', is a clump of mold which exists in a body cavity such as a paranasal sinus or an organ such as the lung. By definition, it is caused by fungi of the genus "Aspergillus".