Pneumonia Disease Research Paper

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Pneumonia is a common disease, which occurs in all age groups. However, pneumonia is the leading cause of death in elderly, people who are chronically and terminally ill, and children under five years old worldwide. It can result from a variety of causes, including infection with bacteria, viruses, fungi, or parasites, and chemical or physical injury to the lungs. Pneumonia is an irregular inflammatory condition of the lung. It is often described as inflammation and abnormal fluid filling of the alveoli of the lung, which are microscopic air filled sacs in the lungs responsible for gas exchange. [2] Typical symptoms associated with pneumonia include cough, chest pain, fever, and difficulty in breathing. Diagnostic tools include x-rays and examination of the phlegm. Bacterial pneumonia is typically treated with antibiotics or antiviral drugs; therefore, treatment depends on the cause of pneumonia. There are vaccines available to prevent certain types of pneumonia. However, the prognosis depends on the type of pneumonia, the appropriate treatment, any complications, and the person's underlying health. [5] Microorganisms, irritants and unknown causes, can cause pneumonia. When pneumonias are grouped this way, infectious causes are the most common type. The symptoms of infectious pneumonia are caused by the infiltration of the lungs by microorganisms and by the immune system's response to the infection. Only a few strains of microorganisms are responsible for most cases of pneumonia however, more than one hundred strains of microorganism can cause pneumonia. Viruses and bacteria are the most common causes of pneumonia. Fungi and parasites are less common causes of infectious pneumonia. [4][1] Viruses invade cells in order to reproduce. Usually, a virus reaches the lungs when viruses carried by the wind are inhaled through the mouth and nose. Once in the lungs, the virus invades the cells lining the airways and alveoli. This invasion often leads to cell death, either when the virus directly kills the cells, or through a type of cell controlled self-destruction. Even more lung damage occurs when the immune system responds to the viral infection. This combination of cell destruction and fluid-filled alveoli interrupts the normal transportation of oxygen into the bloodstream. Many viruses affect other organs, which disrupt many body functions as well as damaging the lungs. Viruses can also make the body more vulnerable to bacterial infections. Therefore, bacterial pneumonia often complicates viral pneumonia. Viruses such as influenza virus, respiratory syncytial virus (RSV), adenovirus, and metapneumovirus commonly cause viral pneumonia. A rare cause of pneumonia except in newborns is the Herpes simplex virus. People with weakened immune systems are also at risk of pneumonia caused by cytomegalovirus. [1] Bacteria usually enter the lung when bacteria carried by the wind are inhaled, but can also reach the lung through the bloodstream when there is an infection in another part of the body. In parts of the upper respiratory tract, such as the nose, mouth and sinuses, and can easily be inhaled into the alveoli is where most bacteria live. Once inside, bacteria may invade the spaces between cells and between alveoli through connecting the pores. This invasion triggers the immune system to send a type of defensive white blood cell to the lungs. The defensive white blood cells engulf and kill the offending organisms, and release cytokines, which causes a general initiation of the immune system. This leads to the chills, fatigue, and fever, which are common in bacterial and fungal pneumonia. The defensive white blood cells, bacteria, and fluid from surrounding blood vessels fill the alveoli and interrupt normal oxygen transport. Bacteria normally travel from an infected lung into the bloodstream, causing serious or even deadly disease such as septic shock, with low blood pressure and damage to multiple parts of the body including the...
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