When the jewelry moves to a different position from where it was initially placed, it is called 'migration'. The migrating jewelry tends to move an extremely short distance from its initial position. This situation is also known as 'parking'. In certain cases, migration of jewelry takes place because the user has sensitivity to the metal used in it. He might also develop allergic reactions to the skin. In such a situation, the user should return to the piercer and get the jewelry replaced by jewelry made from PTFE or other safe materials. Migration may also take place if the jewelry is very big and it disrupts the stretching of the skin, due to which the jewelry moves to another place. Usually, migration is observed in case of naval piercings when there is very little space for the jewelry to be placed in the navel. In such situations, the piercing does not heal well on account of the tension exerted on the tissue by the jewelry. If this happens, the user should go back to the piercer and get the jewelry changed to jewelry that is suitable in shape and size. Migration may also take place on account of the heaviness of the jewelry. The weight of the jewelry is an important factor that affects the duration of the piercing. It has been observed that a person does not immediately notice the migration of his piercing. If the user finds that his piercing is migrating for no obvious reason, it might be due to the heavy jewelry. In this situation, jewelry made from lightweight material such as titanium or niobium or PTFE and other biocompatible plastics should be utitilised. Another reason due to which migration takes place is due to the gauge of the jewelry. When the gauge is only about 1 to 2 mm, the jewelry can easily travel through the skin and migrate. Usually, jewelry having a small gauge are used in abdomen and genital piercings and hence, migration is commonly observed in these piercings. It is advisable to use jewelry with a gauge of 1.6 mm and more for abdominal and surface piercings, 2.4 mm and more for male genital piercings and 1.6 mm and more for female genital piercings. Apart from changing the appearance of the piercing, migration also causes the problem of rejection if it is not taken care of. Rejections are generally observed in case of eyebrow and navel piercings. Rejection of jewelry takes place for reasons same as that for initial migration. However, in case of rejection, the jewelry is forcefully expelled by the body and it can be quite painful to deal with. Soreness and redness may develop around the area of the piercing. The skin also becomes thinner as the jewelry moves. Ultimately there is only a minimal amount of skin holding the jewelry and it keeps on thinning further. It becomes so thin that it cannot bear the weight of the jewelry and it falls out. When the jewelry falls out in this manner, it leaves behind a large amount of scar tissue and a mark at the area where the jewelry was finally held. If thinning out of the skin is observed, it would be advisable to remove the jewelry before it falls off on its own. This can help avoid large amounts of scar tissue and damage to the skin at a later stage.