Lumbar Spondylosis with Radiculopathy: This condition is a common cause of lower back pain that radiates to the hips, calves, and feet due to the degeneration of the lumbar spine and compression of nerve roots. The bilateral nature of the pain suggests a central or widespread process affecting multiple nerve roots.

Peripheral Artery Disease (PAD): PAD can cause pain in the calves and feet, especially during walking, which improves with rest. The bilateral involvement and the inclusion of hip pain could suggest a more proximal arterial involvement.
Diabetic Neuropathy: This condition can cause bilateral pain, numbness, and tingling in the feet and calves, and sometimes the hips, due to nerve damage from diabetes.
Fibromyalgia: A chronic condition characterized by widespread musculoskeletal pain, fatigue, and tenderness in localized areas, which could include the lumbar region, hips, calves, and feet.

Cauda Equina Syndrome: A serious condition that occurs when the nerves in the spinal canal are compressed, leading to pain, numbness, and weakness in the lower back, hips, and legs. It can also cause bladder and bowel dysfunction. Early diagnosis and treatment are crucial to prevent permanent damage.
Spinal Stenosis: Narrowing of the spinal canal can compress the spinal cord or the nerves that travel through the spine to the legs, causing pain, numbness, and weakness in the legs, calves, and feet.
Aortic Aneurysm or Aortoiliac Occlusive Disease: These vascular conditions can cause severe, acute pain in the lower back, hips, and legs due to either the rupture of an aneurysm or significant reduction in blood flow to the lower limbs.

Reflex Sympathetic Dystrophy (Complex Regional Pain Syndrome): A chronic pain condition characterized by severe, burning pain and sensitivity in one of the limbs after an injury or trauma, which could potentially involve multiple areas if the condition is widespread or if there are multiple traumatic incidents.
Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues, which could lead to musculoskeletal pain, including in the lumbar region, hips, calves, and feet, due to joint hypermobility and tissue fragility.
Neurodegenerative Diseases (e.g., Amyotrophic Lateral Sclerosis, Multiple System Atrophy): These conditions can cause a wide range of neurological symptoms, including pain, weakness, and muscle wasting in various parts of the body, including the lower limbs.