The body's response to injury is called inflammation. Physical traumas such as sprain, strain or bruise are most common, whereas injuries can also occur from bacterial or viral infections, heat or any sort of chemical injury. Trauma causes direct damage to cells in the immediate area of injury, causing bleeding. A stream of events is initiated due to bleeding that results in the inflammatory process, which promotes healing of the injured tissue.
Acute and chronic are terms commonly used to refer to the duration or the length of the problem, giving inaccurate information about the actual stage of inflammation. Progression from acute to chronic inflammation can result from persistent injury or individual factors such as, diabetes, corticosteroid use, blood disorders, etc.
Acute swelling is short lived, lasting for only a few days. If it lasts longer, it is referred to as chronic inflammation. Chronic inflammation may last for weeks, months or beyond.
In order to determine if the condition of the injury is in the acute, subacute or chronic inflammatory stage, an adequate case history is needed along with assessment. The assessment should include a visual scan, active muscle testing, passive range of motion testing and resisted isometric muscle tests and palpation of the structure involved. A physiotherapist can thoroughly examine a prolonged chronic stage if it is not healing properly.