Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome, or ARDS, occurs when there is a malfunction of the lungs due to injury of the small air sacs or alveoli, and the surrounding capillaries. When this injury occurs, blood and fluid leak into the spaces between the air sacs, and eventually into the air sacs themselves, resulting in major breathing difficulties, hence the name. ARDS develops as a result of any disease that directly or indirectly injures the lungs.
Alpha-1 Antitrypsin Deficiency
Alpha-1 Antitrypsin deficiency is an inherited disorder that may cause lung or liver disease. Normally, the protein alpha-1 antitrysin, is released into the bloodstream and travels to the lung where it protects the lungs from the destructive actions of common illnesses and exposures, particularly tobacco smoke. People with a deficiency of this protective protein often suffer from progressive lung damage known as emphysema. Unlike the common form of emphysema seen in otherwise healthy individuals who have smoked for many years, this alpha antitrypsin deficiency form of emphysema may occur at an unusually young age and after minimal exposure to tobacco smoke.
Certain dusts, particularly those found in mines and other work places, affect the body in different ways. Some are not dangerous. Others bring injury, even death. The lung diseases caused by dusts are called pneumoconiosis. The name of each pneumoconiosis comes from the dust that produces it. The best known because it is the most common is silicosis. Silicosis comes from breathing in silica, or quartz dust. Asbestosis caused by inhaling asbestos fibers in the mining or milling of asbestos, in the textile, cement and insulating industries. Berylliosis caused by inhaling beryllium dust. Baritosis, Siderosis, Stannosis caused by inhaling dusts of barium sulphate, iron oxide (arc-welding fumes) or tin oxide respectively. Coal Workers’ Pneumoconiosis caused by inhaling coal dust.
Infants and older children get it more often than adults, but adults get it too. Unless there are complications, it is not life threatening, but it can be a social embarrassment.
Bronchiectasis is a relatively rare condition that affects the lungs. In this disorder the bronchial tubes become enlarged and distended forming pockets where infection may gather. The walls themselves are damaged which results in impairment to the lung’s complex cleaning system. The tiny hairs, called cilia – which line the bronchial tubes and sweep them free of dust, germs and excess mucus – are destroyed. When this cleaning system is not working effectively dust, mucus and bacteria accumulate. Infection develops and is difficult to remove.
Bronchopulmonary Dysplasia (BPD)
Bronchopulmonary Dysplasia (BPD) is a type of lung disease that some premature infants get during the first few months of life. Premature infants often need extra oxygen and help in breathing the first few days of life. BPD seems to be a reaction of the baby’s lungs to the oxygen and the pressure used to keep his lungs working normally. We still don’t know why premature babies get this disease. We don’t have any way of preventing it. We do know that the more oxygen and/or pressure that the baby needs over the first weeks of life, the greater the risk of BPD.
Cancer of the Lungs
Cancer is a disease in which abnormal cells in some organ or tissue go out of control, growing and increasing in number. Normal cells reproduce themselves throughout life, but in an orderly and controlled manner. Normal growth occurs, worn out tissues are replaced and wounds heal. When cells grow out of control and form a mass, the mass is called a tumor. Some tumors grow and enlarge only at the site where they began and these are referred to as benign tumors. Other tumors not only enlarge locally but also have the potential to invade and destroy the normal tissue around them and to spread to distant parts of the body. Such tumors are called malignant tumors, or cancer. Distant spread of a cancer occurs when malignant cells detach themselves from the original (primary) tumor, are carried to other parts of the body through the blood or lymphatic vessels and establish themselves in the new site as an independent (secondary) cancer. A tumor that has spread in this manner is said to have metastasized and the secondary tumor (or tumors) is called a metastasis (or metastases).
What is lung cancer?
Because of the different manner in which tissue cells in the same organ system may respond to varying types of exposure to cancer producing agents, several different types of cancer may be found in any organ. This is well illustrated by the primary cancers affecting the lung which are described below. The first three types arise in the lining membrane of the airway in the area most exposed to inhaled pollutants.
§ Squamous cell cancer represents the largest number of lung cancers (approximately 40%-45%).
§ Large cell undifferentiated cancer is found in about 5%-10% of lung cancer cases.
§ Small cell cancers (small cell undifferentiated lesions) account for 15%-20% of all lung cancer. Because it spreads rapidly from its characteristically central location, surgery is rarely the best treatment. However, encouraging results have been obtained with chemotherapy with this kind of lung cancer.
§ Adenocarcinoma usually arises in the outlying areas of the lung and accounts for 25%-30% of all lung cancers. The disease may occur in nonsmokers.
§ Bronchioloalvealar carcinoma arises in even more outlying areas and accounts for less than 5% of the total number of cases. It may also occur in non-smokers.
§ Rare cancers of other types may be found, although they too represent a very small percentage (less than 5%) of the total number of cases.
The bronchi are air passages connecting the windpipe (trachea) with the sacs of the lung (alveoli) where oxygen is taken up by the blood. Bronchitis is an inflammation of the bronchi causing excessive mucous production and swelling of the bronchial walls.
Many people suffer a brief attack of acute bronchitis with fever, coughing and spitting when they have a severe cold. Chronic bronchitis, however, is the term applied when this coughing and spitting continue for months and return each year, generally lasting slightly longer each time. Undue breathlessness on exertion is eventually noticed, due to obstruction to air flow in the air passages caused by swelling of the bronchial wall and the presence of mucus that cannot be cleared.
Emphysema is a disease in which there is destruction of the walls of the air sacs of the lung, and it is frequently preceded by chronic bronchitis. Emphysema adds to the breathlessness suffered by the patient with chronic bronchitis.
A chronic cough is not a disease in itself. It is a sign of something wrong with the breathing system. That’s why it isn’t smart to take cough medicine for more than a week or two unless your doctor tells you to. Medicine may help with the cough, but meanwhile the underlying illness can be getting steadily worse.
The most likely causes of chronic cough are: lung cancer…bronchitis (inflammation in the lung tubes)…bronchiectasis (in which pus pockets form along the tubes)…tuberculosis…other lung diseases.
Many different viruses can cause a cold. Over a hundred have been identified so far.
A virus is a disease-producing agent so small that it goes right through the very fine filter that stops bacteria.
These cold-causing viruses are present in great numbers in your nose and throat when you have a cold. They are carried on the droplets you expel when talking, coughing, or sneezing.
Clinically, croup (laryngo tracheo broncho bronchiolitis) has often been thought of as either “spasmodic” or “viral” in origin. In truth, there is often overlap, with a mild viral illness setting up the airway for eosinophilis action. This occurs in the larynx and trachea in croup, the bronchi in asthma. Again, we see considerable overlap clinically, hence the child with a croupy cough and stridor who improves with Ventolin and Atrovent, due to a bronchial component. Sometimes wheeze, being the more musical of the two sounds, is less easily heard than the stridor.
It is believed that emphysema often is a late effect of chronic infection or irritation of the bronchial tubes. These tubes, the bronchi, connect the windpipe with the lungs. The bronchi look like branches of a tree, with the branches becoming smaller and smaller until each one ends in a cluster of tiny air spaces in the lung. From these tiny spaces (alveoli) oxygen enters the blood when air is breathed in, and waste gas (carbon dioxide) is removed from the lungs by breathing out.
When the bronchi become irritated, some of the airways may be obstructed, trapping air in the lung beyond them. Or the walls of the tiny air spaces may tear, for various reasons. The small blood vessels in the walls disappear. Less contact between blood and air results.
If infection or irritation continues or is repeated for a long time and the stretching and destruction of the walls of the air spaces goes on, the lungs as a whole may become enlarged, at the same time becoming less efficient in exchanging oxygen for carbon dioxide. Enlarged lungs is what gives the disease its name, emphysema (which is a Greek word meaning “Inflation”).
Cigarette smoking contributes to the destructive processes that end up as emphysema.
It is a disease that people working with moldy hay can get from breathing the millions of tiny mold spores shaken out of a bale of moldy hay. Over time, some people develop an allergic reaction to them. The symptoms are serious, and once the allergic reaction begins, the person will always have the potential for symptoms with hay mold exposure.
Hantavirus disease is a rare, but potentially fatal infection spread by deer mice and possibly by other rodents. It is transmitted to people when they inhale airborne particles contaminated by the saliva or excretions of infected rodents. Controlling rodents, identifying sources of infection, cleaning buildings and work sites and minimizing exposures will reduce the risk of infection. Flu-like or pneumonia symptoms following potential exposures to sources of infection should be promptly reported to a doctor for treatment.
It begins as a flu-like illness. The initial symptoms include fever, muscle aches, cough, headaches, nausea and vomiting. As the disease worsens, pneumonia symptoms may develop. Fluid builds up in the lungs, making it difficult to breathe. Death may occur at this stage.
The initial symptoms of the disease may appear from one to six weeks after the exposure, with an average of from two to three weeks. Once the initial symptoms appear, the disease can progress rapidly and become life-threatening within a few days
Anyone can develop an allergy to a common substance, but those who do usually have inherited the tendency as a family trait. The sensitivity is developed after exposure to the substance.
During the seasons when plants are pollinating, everyone in the vicinity is exposed. People with the tendency may develop sensitivity to any one or more of the pollens, although certain pollens are more allergenic — more likely to cause allergic reaction — than others.
Pollens that are light enough to be windborne are the offenders for most hay fever sufferers. Heavier pollens that are borne from plant to plant by bees and other insects can also be allergens, but they cause trouble only when a person comes into direct contact with the plant. Airborne pollens can penetrate anywhere, indoors and out, and are most numerous at the height of the pollinating season for the particular plant
Histoplasmosis is caused by a fungus (mold), an extremely simple form of plant life. (Other familiar fungi are mushrooms, yeast and mildew.) The particular fungus, or plant, that causes this disease is known as histoplasmosisplasma capsulatum. It is tiny and light enough to load in the air when stirred up with dust.
Once it is breathed in, the fungus gets down into the lungs. In effect, it takes root there like a seed and continues to live. The tiny plants increase in number within the lungs simply by dividing themselves in two – over and over again.
Influenza is much worse than a bad cold. Commonly know as “the flu” – its real name is influenza, an infection in the airways caused by the influenza virus. Flu is easily caught and easily spread. And although some symptoms may be cold-like, they are far more serious: headache, chills and a dry cough are rapidly joined by body aches and fever. While the fever declines on the second or third day of the illness, full recovery may take up to 6 weeks. Influenza can lead to severe complications for thousands each year. While most people recover fully, influenza may lead to more severe and life-threatening illnesses, such as pneumonia, resulting in hospitalization and even death. However, vaccination is the only prevention measure that has been proven to reduce mortality rates caused by influenza
Legionellosis is an infection caused by the bacterium Legionella pneumophila. The disease has two distinct forms:
Legionnaires’ disease, the more severe form of infection which includes pneumonia, and Pontiac fever, a milder illness.
People of any age may get Legionnaires’ disease, but the illness most often affects middle-aged and older persons, particularly those who smoke cigarettes or have chronic lung disease. Also at increased risk are persons whose immune system is suppressed by diseases such as cancer, kidney failure requiring dialysis, diabetes, or AIDS. Those that take drugs that suppress the immune system are also at higher risk.
Pontiac fever most commonly occurs in persons who are otherwise healthy. Pontiac fever requires no specific treatment.
Outbreaks of legionellosis have occurred after persons have breathed mists that come from a water source (e.g., air conditioning cooling towers, whirlpool spas, showers) contaminated with Legionella bacteria. Persons may be exposed to these mists in homes, workplaces, hospitals, or public places. Legionellosis is not passed from person to person, and there is no evidence of persons becoming infected from auto air conditioners or household window air-conditioning units.
Lymphangioleiomyomatosis (LAM) is a rare lung disease that is characterized by an unusual type of muscle cell that invades the tissue of the lungs, including the airways, and blood and lymph vessels. Over time, these muscle cells form into bundles and grow into the walls of the airways, and blood and lymph vessels, causing them to become obstructed. Although these cells are not considered cancerous, they act somewhat like cancer cells in that they grow uncontrollably throughout the lung. Over time, the muscle cells block the flow of air, blood, and lymph to and from the lungs, preventing the lungs from providing oxygen to the rest of the body.
Lung transplants are needed when the lungs are damaged and unable to support your body’s need for oxygen. Some diseases that cause the lungs to fail include COPD (chronic obstructive pulmonary disease), pulmonary fibrosis, cystic fibrosis and sarcoidosis.
Pleurisy is an inflammation of the pleura. There are two pleurae, one around each lung. The pleura is a two-ply membrane that both encloses the lung and lines the chest cavity.
This two-layer protective wrapping fits closely around the lung, with, normally, no actual space between the inner and outer layers. The layers are joined at the edges, so that the pleura might be compared to a closed balloon, completely empty of air and wrapped tightly around the outside of each of the lungs.
Only a thin Iubricating layer of fluid is between the inner pleural lining and the outer one. Ordinarily, the smooth linings and lubricating fluid serve to allow the lung free movement within the chest for normal breathing. The almost non-existent space occupied by the lubricant can develop into what is called a pleural cavity if its fluid contents increase.
Pneumonia is an inflammation or infection of the lungs. The lungs’ air sacs fill with pus, mucus, and other liquid and can not function properly. Oxygen can not reach the blood. If there is insufficient oxygen in the blood, body cells can not function properly and may die.
Lobar pneumonia affects a section (lobe) of a lung. Bronchial pneumonia (or bronchopneumonia) affects patches throughout both lungs.
A pneumothorax is a collection of air between the outside surface of the lung and the inside surface of the chest wall. These two surfaces are lined with a smooth membrane called pleura and normally are in contact with each other, but they can become separated when air, fluid or blood collects between them.
A pneumothorax can occur whenever the surface of the lung is ruptured, allowing air to exit from the lung into the pleural space. It can occur when some injury punctures the chest wall, allowing outside air to enter the pleural space. A spontaneous pneumothorax occurs without chest trauma, and is usually due to the rupture of a small cyst on the lung surface. Such cysts may occur without any associated lung disease, or they can develop due to a variety of underlying lung disorders, emphysema being the most common.
Primary Alveolar Hypoventilation Syndrome
This syndrome consists essentially of respiratory failure in patients with normal lungs and normal chest walls. In most individuals, there is normal conscious control of ventilation but failure of automatic control, particularly during sleep. Syndromes of alveolar hypoventilation throw light on the complexity of the factors that may underlie the development of respiratory failure in a wide variety of circumstances. Hypoventilation may occur in association with obesity and as a consequence of obstructive sleep apnea.
Pulmonary Alveolar Proteinosis
People with this disease have excess deposits of protein in the air sacs (alveoli) in their lungs. The excessive protein reduces the oxygen level in the blood making them very tired, weak and depressed. There is no known cause or cure for this disease. The only known treatment is lung lavages (washing of the lungs).
Pulmonary embolus is a blockage of an artery in the lungs by fat, air, tumor tissue, or blood clot .
The term Pulmonary Fibrosis describes the abnormal formation of fibrelike scar tissue in the lungs. It can be a mild or a severe disease. Pulmonary fibrosis is a complicated, chronic illness that can derive from many different causes.
Pulmonary fibrosis is the abnormal formation of fiberlike scar tissue in the lungs. The scar formation is preceded by, and associated with, inflammation.
If the disease progresses, the lung tissues eventually thicken and become stiff. The work of breathing then becomes difficult causing breathlessness. It can also be fatal.
The alveoli are affected. Fibrosis twists them out of shape. Lung capillaries (small blood vessels) also can be distorted by pulmonary fibrosis. In addition, the tissues between and surrounding the alveoli are changed by fibrosis, thus completely deranging the basic architecture of the inner lung. These “in-between” spaces are called the “interstitium”.
This condition has a number of causes and is known by many different names. “Interstitial pulmonary fibrosis” is perhaps the most common name, but other terms frequently used include: “fibrosing alveolitis”, “intersititial pneumonitis” and “Hamman-Rich syndrome”.
Pulmonary hypertension is a rise in pressure within the pulmonary artery that is caused either by a reduction in volume of the pulmonary circulation or by an elevation of pressure in the left atrium or left ventricle. Pulmonary heart disease is said to be present if the right ventricle enlarges in response to the pulmonary hypertension and if the hypertension is due to a disorder of the pulmonary circulation rather than of the left side of the heart.
Pulmonary hypertension may result from several processes that reduce the volume of the pulmonary circulation. One such process is surgical removal of large amounts of lung tissue. Pulmonary blood vessels also can be occluded with thromboemboli. Alternatively, they may be replaced by scar tissue in patients with idiopathic pulmonary fibrosis. Finally, the pulmonary circulation may be eaten away by emphysema.
The most common cause of pulmonary hypertension is narrowing of the pulmonary capillaries in response to a low oxygen pressure in adjacent alveoli. In patients with localized disease processes such as pneumonia this response favours gas exchange by forcing blood to better ventilated regions of the lung. However, when all the alveoli have a low oxygen pressure, as occurs a high altitude and in severe respiratory disorders such as chronic bronchitis and emphysema, pulmonary vessel narrowing becomes generalized. The right ventricle therefore must generate a higher pressure to perfuse the pulmonary circulation. This prompts it to increase in size to pump more forcefully.
Despite this protective mechanism, heart muscle performance worsens. At the same time, pressure rises even further within the right ventricle as its output falls. Pressure then increases in the veins that return blood to the right ventricle from the periphery of the body, forcing water to leak from them and collect in tissues. This process first is noticeable as edema in the legs but eventually may involve the entire body. Left ventricular output also diminishes because less blood is traversing the lungs.
Respiratory Syncytial Virus
RSV or respiratory syncytial virus, is the most frequent cause of serious respiratory tract infections in infants and children younger than 4 years of age. This is such a common virus that virtually all children have been infected by RSV by the age of 3. In most young children, it results in a mild respiratory infection that is not distinguishable from a cold
Pronounced sar-coy-dough-sis, it is a chronic condition that may affect almost any part of the body. Sarcoidosis is characterized by a persistent nodular inflammation of the involved tissues. Lungs, lymph nodes, eyes, skin, liver and spleen are most often involved, but almost any tissue or organ of the body may be affected
Severe Acute Respiratory Syndrome
Severe Acute Respiratory Syndrome or SARS is characterized by fever higher than 38.0 degrees Celsius and one or more respiratory symptoms including cough, shortness of breath, and difficulty breathing. According to the World Health Organization, SARS is spread from person to person but only through close contact with a case. In some cases the respiratory illness progresses to severe respiratory difficulty and death.
Sudden Infant Death Syndrome (SIDS)
SIDS, also known as crib death or cot death, is the most common cause of death in the post-neonatal period. As many as 1 in 10 Neonatal Intensive Care Unit patients with the diagnosis of chronic lung disease, with or without a tracheostomy, when discharged may die suddenly at home without apparent reason, only some of which are appropriately classified as SIDS.