It works by promoting good blood flow, which brings nutrients and agents of the immune system to combat the infection while draining away toxins from the affected areas. (petsmagazine.com.sg)
Maintaining good blood flow immediately after the head injury is also important to minimize the damage suffered to the brain. (grayandwhitelaw.com)
In the 2005 study, subjects who watched funny movies had more relaxed blood vessels, meaning better blood flow. (womenshealthandfitness.com.au)