Belly button fever is usually caused by inflammation of the belly button. The causes of navel inflammation are as follows: 1. It is an inflammatory reaction in the local skin due to bacterial infection in various cases. 2. The navel harbors dirt, which can lead to bacterial multiplication, resulting in infection, causing an inflammatory reaction and fever. 3. Patients usually do not pay attention to personal hygiene, and the infection is caused by button digging the navel at any time. 4. Repeated navel inflammation and fever may be due to their own Immune low situation. At this time, because the body can not eliminate pathogens in a timely manner and cause infection, there will be frequent fever in the navel.