Diabetic Neuropathy: This is a common cause of bilateral lower extremity burning pain, especially in patients with a history of diabetes. The pain is often symmetrical and can be accompanied by other symptoms such as numbness and tingling.

Peripheral Artery Disease (PAD): PAD can cause burning pain in the lower extremities, especially during exercise or at night. The pain is often relieved by rest.
Chronic Venous Insufficiency: This condition can cause burning pain, swelling, and skin changes in the lower extremities due to poor blood flow.
Fibromyalgia: While not exclusively a lower extremity condition, fibromyalgia can cause widespread pain, including burning pain in the legs.
Vitamin Deficiency (B12): A deficiency in vitamin B12 can cause neurological symptoms, including burning pain in the lower extremities.

Deep Vein Thrombosis (DVT): DVT can cause severe, burning pain in one leg, and it is essential to diagnose and treat promptly to prevent pulmonary embolism.
Compartment Syndrome: This is a medical emergency that can cause severe, burning pain in the lower extremities due to increased pressure within the muscle compartments.
Infection (Cellulitis or Abscess): Infections can cause burning pain, redness, and swelling in the lower extremities, and it is crucial to diagnose and treat promptly to prevent serious complications.

Erythromelalgia: A rare disorder that causes burning pain, heat, and redness in the hands and feet.
Complex Regional Pain Syndrome (CRPS): A rare condition that can cause severe, burning pain in one limb after an injury or trauma.
Amyloidosis: A rare condition that can cause burning pain in the lower extremities due to the deposition of abnormal proteins in the nerves.
Heavy Metal Poisoning: Exposure to heavy metals like arsenic or lead can cause burning pain in the lower extremities, among other symptoms.