Peripheral Neuropathy: This condition is characterized by damage to the peripheral nerves, which can cause numbness, swelling, and other symptoms in the feet. The 3-month duration suggests a chronic process, and peripheral neuropathy is a common cause of such symptoms.

Chronic Venous Insufficiency: This condition occurs when the veins have problems returning blood from the legs to the heart, leading to swelling, numbness, and other symptoms in the feet and legs.
Peripheral Artery Disease (PAD): PAD involves the narrowing or blockage of the blood vessels outside the heart, which can cause numbness, swelling, and pain in the feet and legs.
Diabetic Neuropathy: If the patient has diabetes, diabetic neuropathy could be a likely cause of the symptoms, as high blood sugar levels can damage the nerves over time.

Deep Vein Thrombosis (DVT): Although less likely, DVT is a potentially life-threatening condition that requires immediate attention. It involves the formation of a blood clot in the deep veins of the legs, which can cause swelling, numbness, and pain.
Compartment Syndrome: This is a serious condition that occurs when pressure within the muscles builds to dangerous levels, cutting off blood flow and causing numbness, swelling, and pain.
Neoplastic Processes: In rare cases, numbness and swelling in the foot could be symptoms of a tumor compressing nerves or blood vessels.

Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the hands and feet, which could also present with swelling and numbness.
Reflex Sympathetic Dystrophy (RSD): A rare condition that causes chronic pain, swelling, and changes in skin temperature and color, often in response to an injury.
Sarcoidosis: A rare disease that can cause inflammation and damage to various parts of the body, including the nerves and blood vessels, leading to symptoms like numbness and swelling in the feet.