2. Genetics
There are some rare conditions that a person may inherit that might cause your lips to swell periodically. One example is hereditary angioedema. This hereditary disorder causes a person’s lips to swell from time to time. In this type of case, a person is born without some of the proteins being produced in the body. These proteins are important when it comes to maintaining the blood vessel walls.
When these proteins are not present, it can cause the lips and the mouth to swell as the blood vessel walls break down or are simply not as strong as they should be. If you are noticing that your lips swell periodically, it is a good idea to discuss this with your doctor. It could be the sign of an underlying health issue. People who suffer from a genetic disorder may simply have to live with swollen lips at certain times.