Aetiological Classification of Disease - Essay Example

"Aetiological Classification of Disease" is a great example of a paper on infections. 
A disease is an abnormal condition of a system, organ, part, or organism. It is characterized by a cluster of symptoms and signs that result from causes such as genetic and inherited, congenital and developmental, environmentally induced, metabolic, nutritional, inflammatory, infectious, immunology, and traumatic (Ge, Fellay & Goldstein 2009, p. 400). On the other hand, etiology refers to the study of why and the way diseases occur. Aetiological classifications are especially useful for the prevention of diseases, and this paper will define the basic aetiological classification of disease which will include the causes mentioned above.

Infectious diseases are comprised of clinically evident medical symptoms (Reddy, Gill & Wu 2012, p. 610). They occur when pathogenic biological agents such as viruses and microorganisms such as bacteria infect the host organism and grow in or on them (Kayser, Bienz & Eckert 2009, p. 398). Infectious diseases can be transmitted by animal or insect bites, from person to person, or acquired by the ingestion of contaminated water and food. Genetic and hereditary diseases are the ones that occur because of the defects in the genes a parent that is transmitted to their children (Ryan & Ray 2007, p. 69). Examples of genetic and hereditary diseases include diabetes mellitus and hypertension. Inflammation is one of the composite biological responses to harmful stimuli by vascular tissues and can either be acute or chronic (Pedersen 2013, p. 1339). General causes of inflammatory diseases include burns, trauma, chemical irritants, alcohol, and stress, and examples are appendicitis, dermatitis, tendonitis, cystitis, and tonsillitis (Shoelson, Lee & Goldfine 2006, p. 1795). While acute inflammatory diseases are specifically caused by injured tissues and bacterial pathogens, chronic ones are caused by persistent acute inflammation mainly because of non-degradable pathogens. Congenital and developmental diseases are present at birth and are caused by prenatal infections, hereditary factors, or defects in the development of the child (Golden & Peterson 2009, p. 181). Examples include cleft palate and cleft lip. Metabolic diseases occur due to abnormalities or disturbances in the complex metabolic processes and they include hyperthyroidism and diabetes mellitus. The immune system’s primary role is to detect and destroy microorganisms that invade the body and the protective mechanisms are either innate or adaptive (Timmerman, Flynn & Pence 2008, p. 1276). However, both insufficient and excessive immune function can lead to diseases. For example, the insufficient immune function will cause immunodeficiency as manifested by an individual’s increased vulnerability to infection. On the other hand, Excessive immune function will cause autoimmunity and hypersensitivities (Brandt, C & Pedersen, B 2010, p. 1048).

Generally, excessive responses by the innate immune mechanism may trigger inappropriate inflammation under certain conditions and damage nearby tissues. Traumatic diseases are basically due to serious physical injury to the body (Golden & Peterson 2009, p. 198). The injury may be caused by an accident or intentional acts of violence, with fractures being the best example. Traumatic diseases may also result from severe mental or emotional distress such as those that result from an experience an individual has been through. Nutritional diseases are caused by either excesses or deficiencies in the diet. For example, the lack of vitamin C in the diet will cause scurvy; iron deficiency will cause anemia, and rickets will be caused by the lack of vitamin D. Further, nutritional diseases will also comprise of developmental abnormalities that could otherwise have been prevented by proper diet.