Chronic Venous Insufficiency: This condition is characterized by the veins having problems returning blood from the legs back to the heart due to valve issues or blockage. It often presents with swelling, skin thickening, and a shiny appearance of the skin in the affected leg, which matches the symptoms described.

Heart Failure: Fluid buildup due to heart failure can cause swelling in the legs, which might appear shiny due to the stretched skin. The age of the patient increases the likelihood of heart failure.
Lymphedema: This is a condition where the lymphatic system is blocked or damaged, leading to a buildup of fluid in the legs, causing swelling. It can also cause the skin to appear shiny.
Deep Vein Thrombosis (DVT) with Post-Thrombotic Syndrome: While DVT itself might not cause a shiny appearance, post-thrombotic syndrome, which can develop after a DVT, can lead to chronic swelling and skin changes.

Cellulitis: A bacterial infection of the skin that can cause redness, swelling, and warmth. It's crucial to diagnose and treat promptly to prevent serious complications.
Necrotizing Fasciitis: A severe infection that affects the tissue beneath the skin and the fascia, a layer of tissue covering muscles. It's a medical emergency requiring immediate attention.
Compartment Syndrome: Increased pressure within a muscle compartment can lead to severe pain, swelling, and potentially permanent damage if not treated promptly.

Lipedema: A chronic condition characterized by the abnormal growth of fat cells in the legs, leading to swelling. It's less common and might be considered if other diagnoses are ruled out.
Myxedema: A condition associated with hypothyroidism, characterized by thickening of the skin and swelling, which could potentially cause a shiny appearance in the affected areas.
Scleroderma: An autoimmune disease that can cause skin thickening and swelling, potentially leading to a shiny appearance, though it's less likely given the localized nature of the symptoms described.