Inguinal Hernia: This is the most common cause of inguinal swelling and can be direct or indirect. The symptoms can include a bulge in the groin area that may or may not be painful and can often be pushed back into the abdomen.

Hydrocele: A condition characterized by the accumulation of fluid around a testicle, leading to swelling of the scrotum. It can extend into the inguinal canal and cause inguinal swelling.
Varicocele: As mentioned, a varicocele is an enlargement of the veins within the scrotum, similar to varicose veins. It's more common on the left side but can occur on the right, causing a swelling that might be confused with an inguinal mass.
Lymphadenopathy: Enlarged lymph nodes in the groin area can cause swelling and can be due to various reasons including infections, autoimmune diseases, or malignancies.

Testicular Torsion: Although it presents more acutely with severe pain and is less likely to be mistaken for a simple inguinal swelling, it's crucial to consider due to its emergency nature requiring immediate intervention.
Epididymitis: Inflammation of the epididymis, usually due to infection, can cause swelling and pain in the scrotum and inguinal area. It's essential to diagnose and treat promptly to prevent complications.
Malignancy: Though less common, swelling in the inguinal area could be a sign of a tumor, either primary in the inguinal canal or metastatic from another site.

Spermatocele: A cystic structure filled with sperm that arises from the head of the epididymis, which can cause swelling but is usually less noticeable and not typically in the inguinal area.
Cyst of the Canal of Nuck: A rare condition in females, analogous to a hydrocele in males, where a cyst forms in the inguinal canal.
Lipoma or other soft tissue tumors: Benign tumors like lipomas can occur in the inguinal region and cause swelling, though they are less common causes of inguinal swelling.