Blepharitis: This is an inflammation of the eyelids that can cause swelling, redness, and itching. It's a common condition and often the first consideration for eyelid swelling due to its high prevalence.

Allergic Conjunctivitis: This condition occurs when the eyes react to an allergen, leading to symptoms like itching, redness, and swelling of the eyelids.
Hordeolum (Stye): A localized infection or inflammation of the eyelid margin involving hair follicles of the eyelashes or meibomian glands, which can cause swelling, pain, and redness.
Chalazion: A small bump on the eyelid due to a blocked oil gland, which can cause swelling and may become inflamed or infected.

Orbital Cellulitis: A serious infection of the tissues surrounding the eye, which can cause eyelid swelling, pain, and vision changes. It requires prompt medical attention to prevent serious complications.
Thyroid Ophthalmopathy: A condition associated with Graves' disease that can cause eyelid swelling, bulging eyes, and other eye symptoms. Early recognition is crucial for appropriate management.
Basal Cell Carcinoma or Other Eyelid Tumors: Although rare, these can present with swelling and should not be missed due to their potential for serious consequences if left untreated.

Angioedema: A rare condition characterized by rapid swelling of the skin and mucous membranes, which can affect the eyelids and is often associated with an allergic reaction or genetic predisposition.
Wegener's Granulomatosis (Granulomatosis with Polyangiitis): A rare autoimmune disorder that can affect various parts of the body, including the eyes, and cause swelling among other symptoms.
Sarcoidosis: A condition where inflammatory cells form lumps known as granulomas in various parts of the body, including the eyelids, leading to swelling and other symptoms.