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.
Second-degree burns are more serious than first-degree burns but less serious than third-degree burns. Second-degree burns are characterized by swelling, pain, and blisters. They may produce white or splotchy skin. Comparing second-degree burns to third and first degree burns can help treat them appropriately. First-degree burns cause redness, pain, and swelling.