The foreskin area appears edematous for the following common reasons: 1. Inflammation of the foreskin, foreskin inflammation leads to local tissue inflammatory edema, this is more common. 2. After circumcision, foreskin edema is also very common after circumcision, mostly seen in the post-operative period of about 1 week. 3. Foreskin imbrication, foreskin imbrication can not be turned up and back in time, it can lead to foreskin edema. 4. Children with loose foreskin tissues are prone to oedema when they are traumatised or bitten by insects. 5. Hypoproteinemia, when the nutritional status is poor and albumin is low, foreskin oedema can occur, often combined with oedema in other areas such as the limbs.