Final answer:
Following an injury or trauma, inflammation typically starts immediately or within a few weeks. This response includes redness, warmth, swelling, and pain at the site of the injury. Concussions, a mild form of traumatic brain injury, usually heal on their own, whereas severe injuries can lead to permanent damage.
Step-by-step explanation:
What usually starts immediately following injury or within a few weeks after trauma is inflammation. This natural response to injury involves vasodilation and fluid leakage into surrounding tissue, leading to redness, warmth, swelling, and pain. During this process, injured cells alongside mast cells and macrophages release chemical signals triggering the inflammatory response. This can be observed in various types of injuries, including those resulting from sports or accidents leading to concussions or more severe traumatic brain injuries (TBIs).
Following a head injury such as a concussion, which is common in contact sports like football, soccer, and hockey, individuals may experience temporary issues like headaches, drowsiness, and confusion. However, if the trauma is severe, it can lead to permanent brain damage with symptoms that include loss of consciousness, confusion, and difficulty with motor control and cognitive functions such as memory. Recovery from serious brain injuries often requires medication, counseling, and rehabilitation to cope with disabilities.
It's crucial to note that while mild brain injuries like concussions typically heal on their own, severe injuries can have lasting effects, leading to persistent physical and mental disabilities. Similarly, the loss of blood flow to the brain, known as a stroke or cerebrovascular accident (CVA), can result in cell death within hours of the event.