* Suction: When the bottle is pressed against your lip and then quickly pulled away or creates a seal, it creates suction. This suction pulls blood and fluids into the area where the pressure is lowest (inside the bottle's rim).
* Pressure Difference: The suction creates a pressure difference between the area inside the bottle and the surrounding tissue. The higher pressure in the surrounding tissue pushes fluids into the area of lower pressure.
* Increased Blood Flow: The body responds to the pressure and suction by increasing blood flow to the area. This is part of the body's natural healing response, even though there may not be a significant injury. The increased blood flow contributes to the swelling and redness.
* Fluid Leakage: The pressure and disruption can cause small blood vessels (capillaries) to become more permeable, allowing fluid (plasma) to leak out into the surrounding tissues. This fluid accumulation is a major cause of the swelling (edema).
* Inflammatory Response: The body may also initiate a mild inflammatory response to the suction and pressure, further contributing to the swelling and redness.
In essence, the swelling is a localized reaction to the temporary distortion and pressure imbalance caused by the bottle's suction. The body sends fluids to the area, leading to a temporary "plumping" effect, which can also appear as swelling.