Heart Failure: This condition often presents with bilateral lower extremity edema due to fluid overload and increased venous pressure. The intermittent swelling of a finger could be related to fluctuations in fluid status or could be a separate, unrelated issue but heart failure's commonality and the edema pattern make it a leading consideration.

Chronic Venous Insufficiency: This condition can cause bilateral lower leg edema due to the inability of veins to return blood to the heart properly, leading to fluid accumulation in the legs. The swollen finger might not be directly related but could be due to a separate venous issue or another condition.
Lymphedema: Although more commonly unilateral, lymphedema can present bilaterally and cause significant edema in the legs. The involvement of a finger could suggest a more widespread lymphatic issue.
Hypothyroidism: This condition can cause generalized edema, including in the lower legs, and potentially affect the hands and fingers, though this would be less common.

Deep Vein Thrombosis (DVT): Although DVT typically presents unilaterally, it's crucial not to miss this diagnosis due to its potential for severe complications like pulmonary embolism. The swollen finger could be unrelated, but any new swelling warrants consideration of DVT.
Nephrotic Syndrome: This condition involves significant protein loss in the urine, leading to hypoalbuminemia and subsequent edema. It's a critical diagnosis not to miss due to its implications for kidney function and the need for specific treatment.
Superior Vena Cava Syndrome: This is a medical emergency where obstruction of the superior vena cava leads to edema and swelling of the upper body, which could include fingers. It's less likely to cause bilateral lower leg edema primarily but is a diagnosis that must be considered due to its urgency.

Sarcoidosis: A systemic disease that can cause edema among many other symptoms, including skin, lung, and eye manifestations. It's less common but could explain widespread symptoms including leg and finger swelling.
Fabry Disease: A genetic disorder that can lead to edema and swelling in various parts of the body, including the legs and hands, due to the accumulation of a particular type of fat in the body's cells.
Erythromelalgia: A disorder that causes burning pain, heat, and redness in the hands and feet, and can sometimes be associated with swelling. It's a rare condition but could potentially explain some of the symptoms if they are primarily limited to the extremities.