Idiopathic scrotal edema: This condition is characterized by the sudden onset of scrotal swelling, often without pain, and is more common in children. It is usually self-limiting and resolves on its own.

Hydrocele: A collection of fluid around a testicle, leading to scrotal swelling. It can be primary (idiopathic) or secondary due to other conditions like injury or infection.
Varicocele: Enlargement of the veins within the scrotum, similar to varicose veins. It can cause swelling and is often painless, though it may cause a feeling of heaviness.
Epididymal cyst: A benign cystic growth on the epididymis that can cause scrotal swelling. These cysts are usually painless and filled with fluid.

Testicular torsion: Although typically painful, some cases can present with minimal or no pain. It is a surgical emergency that requires prompt intervention to save the affected testicle.
Testicular cancer: While often painless, testicular cancer can present with a painless testicular mass or swelling. Early detection is crucial for effective treatment.
Inguinal hernia: An inguinal hernia can cause scrotal swelling if it extends into the scrotum. While often painful, some cases may be painless, especially if the hernia is small.

Filariasis: In areas where filariasis is endemic, it can cause scrotal swelling due to the parasitic infection. This condition is rare in most parts of the world but should be considered in travelers or individuals from endemic areas.
Lymphatic obstruction: Conditions that obstruct lymphatic drainage, such as lymphoma or surgical removal of lymph nodes, can lead to scrotal edema. These conditions are less common and usually have other associated symptoms.
Surgical or traumatic complications: Complications from surgeries in the pelvic area or trauma can lead to scrotal edema. These would typically have a clear history of preceding surgery or injury.