Respiratory disease
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224318928
2008-07-08T09:22:29Z
203.87.209.206
/* Pleural cavity diseases */
{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = Respiratory system complete numbered.svg |
Caption = Respiratory system |
DiseasesDB = |
ICD10 = {{ICD10|J|00||j|00}}-{{ICD10|J|99||j|95}} |
ICD9 = {{ICD9|460}}-{{ICD9|519}} |
ICDO = |
OMIM = |
MedlinePlus = |
eMedicineSubj = |
eMedicineTopic = |
MeshID = D012140 |
}}
'''Respiratory Disease''' is the term for [[disease]]s of the [[respiratory system]]. These include diseases of the [[lung]], [[pleural cavity]], [[bronchial]] tubes, [[trachea]], [[upper respiratory tract]] and of the nerves and muscles of [[breathing]]. Respiratory disease ranges from mild and self-limiting such as the [[common cold]] to life-threatening such as [[bacterial pneumonia]] or [[pulmonary embolism]]. They are a common and important cause of illness and death. In the US, Adults average between 2 and 4 colds a year, children between 6 and 10<ref>{{cite web |url= http://www3.niaid.nih.gov/healthscience/healthtopics/colds/overview.htm|title= National Institutes of Health – common cold|accessdate=2008-05-07 |format= |work= }}</ref>. One in seven people in the UK is affected by some form of chronic lung disease, most commonly [[chronic obstructive pulmonary disease]] and [[asthma]] <ref name = "BLF">{{cite web |url= http://www.lunguk.org/media-and-campaigning/media-centre/lung-stats-and-facts/factsaboutrespiratorydisease.htm|title= British Lung Foundation - Facts about respiratory disease|accessdate=2008-04-19 |format= |work= }}</ref>. Respiratory disease is responsible for over 10% of hospitalizations and over 16% of deaths in Canada<ref name = "PHAC">{{cite web |url= http://www.phac-aspc.gc.ca/ccdpc-cpcmc/crd-mrc/facts_gen_e.html|title= Public Health Agency of Canada - Centre for Chronic Disease Prevention and Control
Chronic Respiratory Diseases |accessdate=2008-05-06 |format= |work= }}</ref>.
The study of respiratory disease is known as [[pulmonology]]. A doctor who specializes in respiratory disease is known as a pulmonologist, a chest medicine specialist, a respiratory medicine specialist, a respirologist or a thoracic medicine specialist.<br /><br />
==Symptoms==
The symptoms of respiratory disease differ depending on the disease. Common symptoms are:
* Shortness of breath or [[dyspnea]] which usually occurs with exercise and can interfere with daily activities. In severe cases, shortness of breath occurs while resting.
* [[Cough]] with or without the production of [[sputum]].
* Coughing blood ([[haemoptysis]]).
* [[Chest pain]]. This may or may not be pleuritic chest pain (that is pain that worsens with the movements of breathing).
* Noisy breathing, either [[wheeze]] or [[stridor]].
* [[Somnolence]].
* Loss of appetite.
* Weight loss.
* [[Cyanosis]], a bluish discoloration of the lips, tongue or fingers.
In some cases respiratory disease is diagnosed without symptoms in the investigation of another disease or through a routine check.
==Diagnostic tests==
Respiratory diseases may be investigated by perfoming one or more of the following tests
* [[Chest x-ray]]
* [[Pulmonary function test]]
* [[Computed tomography scan]]
* [[Microbiological culture|Culture of microorganisms]] from secretions such as [[sputum]]
* [[Bronchoscopy]]
* [[Biopsy]] of the lung or pleura
* [[Ventilation/perfusion scan|Ventilation - perfusion scan]]
* [[Medical ultrasonography|Ultrasound]] scanning can be useful to detect fluid such as [[pleural effusion]]
==Treatment==
Treatment of respiratory disease depends on the particular disease being treated, the severity of disease and the patient. Lifestyle factors such as regular exercise and healthy nutrition are important in preventing and treating respiratory disease. Vaccination can prevent some respiratory diseases. In addition, the following treatments are often used for respiratory diseases:
* Medication, often given in an inhaled form
** [[Glucocorticoid|Corticosteroids]]
** [[Bronchodilators]]
** [[Antibiotics]]
** [[Anticoagulants]]
** Cancer [[chemotherapy]]
** Immune suppressants
* [[Physiotherapy]]
* [[Oxygen]]
* [[Mechanical ventilation]]
* [[Radiotherapy]]
* Surgery
** Removal of a cancer e.g. lobectomy, pneumonectomy
** [[Pleurodesis]]
** Lung volume reduction surgery
** [[Lung transplantation]]
==Respiratory diseases==
Respiratory diseases can be classified in many different ways; by the organ involved, by the pattern of symptoms or by the cause of the disease.
===Obstructive lung diseases===
These are diseases of the lung where the [[bronchial]] tubes become narrowed making it hard to move air in and especially out of the lung.
====Chronic obstructive pulmonary disease<ref name="emedicineCOPD">{{cite web |url= http://www.emedicine.com/emerg/topic99.htm|title= Chronic Obstructive Pulmonary Disease and Emphysema|accessdate=2008-04-19 |author= Kleinschmidt, Paul|date= |work= |publisher=}}</ref>====
{{main|Chronic obstructive pulmonary disease}}
'''[[Chronic obstructive pulmonary disease]]''' (COPD), also known as chronic obstructive airways disease (COAD) or chronic airflow limitation (CAL), is a group of illnesses characterised by airflow limitation that is not fully reversible. The flow of air into and out of the lungs is impaired. This can be measured with breathing devices such as a [[peak flow meter]] or by [[spirometry]]. The term COPD includes the conditions [[emphysema]] and [[chronic bronchitis]] although most patients with COPD have characteristics of both conditions to varying degrees. [[Asthma]] being a reversible obstruction of airways is often considered separately, but many COPD patients also have some degree of reversibility in their airways.
In COPD, there is an increase in [[Airway resistance|airway resistance]], shown by a decrease in the forced expiratory volume in 1 second (FEV1) measured by [[spirometry]]. COPD is defined as a forced expiratory volume in 1 second to forced vital capacity ratio (FEV1/FVC) that is less than 0.7<ref name = "GOLD">{{cite web |url= http://www.goldcopd.com/|title= GOLD – the Global initiative for chronic Obstructive Lung Disease disease|accessdate=2008-05-06 |format= |work= }}</ref>. The residual volume, the volume of air left in the lungs following full expiration, is often increased in COPD, as is the total lung capacity, while the vital capacity remains relatively normal. The increased total lung capacity (hyperinflation) can result in the clinical feature of a "barrel chest" - a chest with a large front-to-back diameter that occurs in some individuals with COPD. Hyperinflation can also be seen on a [[chest x-ray]] as a flattening of the [[diaphragm]].
The most common cause of COPD is cigarette [[smoking]]. COPD is a gradually progressive condition and usually only develops after about 20 [[Pack_year|pack-year]]s of smoking. COPD may also be caused by breathing in other particles and gasses.
The disagnosis of COPD is established through [[spirometry]] although other pulmonary function tests can be helpful. A [[chest x-ray]] is often ordered to look for hyperinflation and rule out other lung conditions but the lung damage of COPD is not always visible on a [[chest x-ray]]. [[Emphysema]], for example can only be seen on [[computed tomography|CT scan]].
The main form of long term management involves the use of [[Bronchodilator|inhaled bronchodilators]] (specifically [[Beta2-adrenergic agonist|beta agonists]] and [[anticholinergics]]) and inhaled [[Glucocorticoid|corticosteroids]]. Many patients eventually require [[Oxygen therapy|oxygen supplementation]] at home. In severe cases that are difficult to control, chronic treatment with oral [[Glucocorticoid|corticosteroids]] may be necessary, although this is fraught with significant side-effects.
COPD is generally irreversible although lung function can partially recover if the patient stops smoking. Smoking cessation is an essential aspect of treatment<ref name="BMJbest">{{cite web |url= http://besttreatments.bmj.com/btuk/conditions/14422.html|title= What is chronic obstructive pulmonary disease (COPD)?|accessdate=2008-04-19 |date= |work= |publisher=}}</ref>. Pulmonary rehabilitation programmes involve intensive exercise training combined with education and are effective in improving shortness of breath. Severe [[emphysema]] has been treated with lung volume reduction surgery with some success in carefully chosen cases. [[Lung transplantation]] is also performed for severe COPD in carefully chosen cases.
[[Alpha 1-antitrypsin deficiency]] is a fairly rare genetic condition that results in COPD (particularly [[emphysema]]) due to a lack of the antitrypsin protein which protects the fragile alveolar walls from protease enzymes released by [[Inflammation|inflammatory processes]].
====Asthma====
{{main|Asthma}}
Asthma is an obstructive lung disease where the [[bronchial]] tubes (airways) are extra sensitive (hyperresponsive). The airways become inflamed and produce excess mucus and the muscles around the airways tighten making the airways narrower. Asthma is usually triggered by breathing in things in the air such as dust or pollen that produce an allergic reaction. It may be triggered by other things such as an [[upper respiratory tract infection]], cold air, exercise or smoke. Asthma is a common condition and affects over 300 million people around the world<ref name = "GINA">{{cite web |url= http://www.ginasthma.com|title= GINA – the Global INitiative for Asthma |accessdate=2008-05-06 |format= |work= }}</ref>.
Asthma causes recurring episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning.
Asthma is diagnosed by the characteristic pattern of symptoms. A [[peak flow meter]] can record variations in the severity of asthma over time. [[Spirometry]], a measurement of lung function, can provide an assessment of the severity, reversibility, and variability of airflow limitation, and help confirm the diagnosis of asthma<ref name="GINA"/>.
Asthma is treated by identifying and removing the triggers that set it off, if possible. The main form of long term management involves the use of inhaled [[Glucocorticoid|corticosteroids]]. [[Bronchodilator|Inhaled bronchodilators]], particularly [[Beta2-adrenergic agonist|beta agonists]] are used to relieve and control symptoms by reducing muscle spasm around the airways. An alternative way to control mild asthma is with a [[leukotriene antagonist]] tablet.
====Other obstructive lung diseases====
* [[Cystic fibrosis]] is an inherited disorder of the CFTR gene, a chloride ion channel. The lack of this channel causes reduced water content of secretions. This affects the mucus secreted as part of the lung's defence and creates sticky, viscous mucus. This makes the lungs more susceptible to infection, inflammation and [[Mucus plug|mucous plugging]].
* [[Bronchiectasis]]
* [[Bronchiolitis]]
* [[Allergic bronchopulmonary aspergillosis]]
In many parts of the world, the most common cause of obstructive lung disease is lung scarring after [[tuberculosis]] infection.
===Restrictive lung diseases<ref name="emedicineRLD">{{cite web |url= http://www.emedicine.com/med/topic2012.htm|title= Restrictive Lung Disease|accessdate=2008-04-19 |author= Sharma, Sat|date= |work= |publisher=}}</ref>===
'''Restrictive lung diseases''' (also known as interstitial lung diseases) are characterised by a loss of [[Pulmonary compliance|lung compliance]], causing incomplete lung expansion and increased lung stiffness. The underlying process is usually pulmonary fibrosis (scarring of the lung). As the disease progresses, the normal lung tissue is gradually replaced by scar tissue interspersed with pockets of air. This can lead to parts of the lung having a honeycomb-like appearance.
The main symptoms are shortness of breath and cough.
In restrictive lung disease, both the FEV1 and FVC 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<ref >{{cite web |url= http://www.spirxpert.com/characteristic6.htm |title= www.spirXpert.com |format= |work= }}</ref>.
Restrictive lung diseases may be due to a specific cause such as:
* [[Asbestosis]] caused by long-term exposure to asbestos dust.
* Radiation fibrosis, usually from the radiation given for cancer treatment.
* Certain drugs such as [[amiodarone]], [[bleomycin]] and [[methotrexate]].
* As a consequence of another disease such as [[rheumatoid arthritis]].
* [[Hypersensitivity pneumonitis]] due to an allergic reaction to inhaled particles.
* [[Acute respiratory distress syndrome]] (ARDS), a severe lung condition occuring in response to a critical illness or injury.
* [[Infant respiratory distress syndrome]] due to a deficiency of [[surfactant]] in the lungs of a baby born prematurely.
Many cases of restrictive lung disease are [[idiopathic]] (have no known cause). Examples are:
* [[Idiopathic pulmonary fibrosis]]
* Idiopathic interstial pneumonia, of which there are several types
* [[Sarcoidosis]]
* [[Eosinophilic pneumonia]]
* [[Lymphangioleiomyomatosis]]
* Pulmonary Langerhan’s cell histiocytosis
* Pulmonary alveolar proteinosis
===Respiratory tract infections===
Infections can affect any part of the respiratory system. They are traditionally divided into upper respiratory tract infections and lower respiratory tract infections.
====Upper respiratory tract infection====
The most common [[upper respiratory tract infection]] is the [[common cold]] however infections of specific organs of the upper respiratory tract such as [[sinusitis]], [[tonsillitis]], [[otitis media]], [[pharyngitis]] and [[laryngitis]] are also considered upper respiratory tract infections.
====Lower respiratory tract infection====
The most common lower respiratory tract infection in is [[pneumonia]], a lung infection. Pneumonia is usually caused by bacteria, particularly [[''Streptococcus pneumoniae'']] in Western countries. Worldwide, [[tuberculosis]] is an important cause of pneumonia. Other pathogens such as viruses and fungi can cause pneumonia for example [[severe acute respiratory syndrome]] and [[pneumocystis pneumonia]]. A pneumonia may develop complications such as a lung abscess, a round cavity in the lung caused by the infection or an empyema, the spread of the infection to the [[pleural cavity]].
===Respiratory tumours===
Tumours of the respiratory system are either malignant or benign.
====Malignant tumours====
Malignant tumours, or cancers of the respiratory system, particularly lung cancers, are a major health problem responsible for 15% of all cancer diagnoses and 29% of all cancer deaths<ref name = "LungCa">{{cite web |url= http://www.lungcancer.org/reading/about.php|title= LungCancer.org|accessdate=2008-05-07 |format= |work= }}</ref>. The majority of respiratory system cancers are attributable to smoking tobacco.
The major types of respiratory system cancer are:
* [[Small cell lung cancer]]
* [[Non-small cell lung cancer]]
** Adenocarcinoma
** Squamous cell carcinoma
** Large cell undifferentiated carcinoma
* Other lung cancers ([[carcinoid]], [[Kaposi’s sarcoma]], [[melanoma]])
* [[Lymphoma]]
* [[Head and neck cancer]]
* [[Mesothelioma]], usually caused by exposure to asbestos dust.
In addition, since many cancers spread via the bloodstream and the entire cardiac output passes through the lungs, it common for cancer [[metastases]] to occur the lung. [[Breast cancer]] may invade directly through local spread, and through lymph node metastases. After metastasis to the [[liver cancer|liver]], [[colon cancer]] frequently metastasizes to the lung. [[Prostate cancer]], germ cell cancer and [[renal cell carcinoma]] may also metastasize to the lung.
Treatment of respiratory system cancer depends on the type of cancer. Surgery (usually removal of part of the lung, a [[lobectomy]] or an entire lung, a [[pneumonectomy]]), [[chemotherapy]] and [[radiotherapy]] are all used. The chance of surviving lung cancer depends on the cancer stage at the time the cancer is diagnosed and is only about 14-17% overall<ref name = "Canadalung">{{cite web |url= http://lung.ca/diseases-maladies/cancer-cancer/treatment-traitement/index_e.php|title= Canadian Lung Association – Lung Cancer|accessdate=2008-05-07 |format= |work= }}</ref>. In the case of metastases to the lung, treatment can occasionally be curative but only in certain, rare circumstances.
====Benign tumours====
Benign tumours are relatively rare causes of respiratory disease. Examples of benign tumours are:
* Pulmonary [[hamartoma]]
* Congenital malformations such as [[pulmonary sequestration]] and [[congenital cystic adenomatoid malformation]] (CCAM).
===Pleural cavity diseases===
Pleural cavity diseases include [[empyema]] and [[mesothelioma]] which are mentioned above.
A collection of fluid in the pleural cavity is known as a [[pleural effusion]]. This may be due to fluid shifting from the bloodstream into the pleural cavity due to conditions such as congestive heart failure and cirrhosis. It may also be due to inflammation of the pleura itself as can occur with infection, [[pulmonary embolus]], [[tuberculosis]], [[mesothelioma]] and other conditions.
A [[pneumothorax]] is a hole in the pleura covering the lung allowing air in the lung to escape into the pleural cavity. The affected lung “collapses” like a deflated baloon. A [[tension pneumothorax]] is a particularly severe form of this condition where the air in the pleural cavity cannot escape, so the pneumothorax keeps getting bigger until it compresses the heart and blood vessels, leading to a life threatening situation.
===Pulmonary vascular diseases===
Pulmonary vascular diseases are conditions that affect the [[pulmonary circulation]]. Examples of these conditions are:
* [[Pulmonary embolism]], a [[Thrombosis|blood clot]] that forms in a vein, breaks free, travels through the heart and lodges in the lungs (thromboembolism). Large pulmonary emboli are fatal, causing sudden death. A number of other substances can also embolise to the lungs but they are much more rare: [[fat embolism]] (particularly after bony injury), amniotic fluid embolism (with complications of labour and delivery), [[air embolism]] (iatrogenic).
* [[Pulmonary arterial hypertension]], elevated pressure in the pulmonary arteries. It can be [[idiopathic]] or due to the efects of another disease, particularly COPD. This can lead to strain on the right side of the heart, a condition known as [[cor pulmonale]].
* [[Pulmonary edema]], leakage of fluid from capillaries of the lung into the [[alveoli]] (or air spaces). It is usually due to congestive heart failure.
* Pulmonary hemorrhage, inflammation and damage to capillaries in the lung resulting in blood leaking into the alveoli. This may cause blood to be coughed up. Pulmonary hemhorrage can be due to auto-immune disorders such as [[Wegener's Granulomatosis]] and [[Goodpasture's syndrome]].
===Disorders of breathing mechanics===
The brain co-ordinates breathing and sends messages via nerves to the muscles of respiration. The muscles produce the movements of breathing. Disorders of the brain’s control of breathing, the nerves or the muscles of respiration can affect the respiratory system.
Common disorders of breathing mechanics are:
* Obstructive [[sleep apnea]]
* Central [[sleep apnea]]
* [[Amyotrophic lateral sclerosis]]
* [[Guillan-Barre syndrome]]
* [[Myasthenia gravis]]
[[Obesity]] is often associated with [[sleep apnea]] and can cause either an obstructive or a restrictive pattern on [[spirometry]]. Obesity reduces the movement of the chest wall which can, in extreme cases, result in the obesity-hypoventilation syndrome, a cause of respiratory failure.
==References==
{{reflist|2}}
[[Category:Diseases]]
[[Category:Pulmonology]]
{{Respiratory pathology}}
{{Certain conditions originating in the perinatal period}}
{{Respiratory physiology}}
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