When one cracks a knuckle, the stretching of the capsule lowers the pressure inside the joint and creates a vacuum which is filled by the gas previously dissolved in the synovial fluid. This creates a âbubbleâ which then bursts producing the characteristic âpoppingâ or âcrackingâ sound.
DOCTORS: Click here for the Professional Version. Burns are injuries to tissue that result from heat, electricity, radiation, or chemicals. Burns cause varying degrees of pain, blisters, swelling, and skin loss. Deep, extensive burns can cause serious complications, such as shock and severe infections. Small, shallow burns may need only to be kept clean and to have an antibiotic cream applied.
On more than one occasion my skin was affected by serious sunburns. I had fever and I was in a lot of pain, but I have never experienced swelling due to sunburn. But, a thing like this can happen in the hardest sunburn cases. You see ultraviolet lights that cause sunburns actually hurt our skin cells. Our immune system sees this as a threat and reacts. The swelling is one of the signs of inflammation. The mechanism of this immune system reaction is very complex.