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Swelling is a transient abnormal enlargement of a body part or area caused not by neoplasm (proliferation of cells) but by accumulation of interstitial fluid (fluid in tissues). It can occur throughout the body (generalized), or it can affect a specific part or organ (localized). Swelling is usually not dangerous and is a common reaction to an inflammation or a bruise.
|Left and right ring fingers of the same individual. The distal phalanx of the finger on the right exhibits swelling due to acute paronychia.|
Swelling is considered one of the five characteristics of inflammation; along with pain, heat, redness, and loss of function.
A body part may swell in response to injury, infection, or disease. Swelling, especially of the ankle, can occur if the body is not circulating fluid well. If water retention progresses to a symptomatic extent, swelling results.
Generalized swelling, or massive edema (also called anasarca), is a common sign in severely ill people. Although slight edema may be difficult to detect to the untrained eye, especially in an overweight person, massive edema is very obvious.
Congenital swellings are present since birth, such as a hemangioma or meningocele. Some congenital swellings may not be discovered until later in life, such as a branchial cyst, dermoid cyst, or thyroglossal cyst.
Inflammatory swelling may be either acute or chronic. The presentations of acute swellings are redness, local fever, pain and impairment of function of the affected organ. The related lymph nodes will be affected and will show signs of acute lymphadenitis. Chronic inflammatory swellings will show the signs of acute inflammatory swellings, but in subdued form. In this case, edema might not occur. Chronic swellings can be differentiated from neoplastic swellings by the fact that neoplastic swellings never recede in size, but inflammatory swellings may show occasional diminution.
Causes of generalized swelling:
Some possible causes of a swollen limb include:
While it is possible for mild swelling to go away on its own, several things can be done to relieve the symptoms or hasten the process. It is important that swelling is treated quickly because it occurs at the fastest rate immediately after the incident that caused it. The RICE first aid method (rest, ice, compression, and elevation) of protecting the affected area has long been taught as a short term solution. The application of oxygen is known to assist in the reduction of swelling.