Chronic Venous Insufficiency: This condition is a common cause of bilateral non-pitting edema, especially when accompanied by leg pain. The edema is typically more pronounced in the lower legs and can be associated with varicose veins, skin discoloration, and a history of prolonged standing or deep vein thrombosis.

Heart Failure: Edema due to heart failure is often bilateral and can be non-pitting. It is usually accompanied by other symptoms such as shortness of breath, orthopnea, and fatigue. The leg pain could be related to decreased perfusion or congestion.
Liver Disease (Cirrhosis): Liver cirrhosis can lead to fluid retention and edema, which may be non-pitting. The edema is often more pronounced in the lower extremities and can be associated with ascites and jaundice.
Nephrotic Syndrome: This condition involves significant proteinuria, leading to hypoalbuminemia, which can cause non-pitting edema. The edema can be widespread, including the lower legs, and is often accompanied by foamy urine and weight gain.
Hypothyroidism: Severe hypothyroidism can cause non-pitting edema (myxedema) and may be associated with leg pain due to muscle aches or carpal tunnel syndrome.

Deep Vein Thrombosis (DVT): Although DVT typically presents with unilateral symptoms, it can occasionally cause bilateral edema and pain. Missing this diagnosis could be fatal due to the risk of pulmonary embolism.
Lymphoma or Other Malignancies: Certain cancers can cause lymphedema or venous obstruction, leading to non-pitting edema. Early detection is crucial for effective treatment.
Sepsis or Infection: Severe infections can cause edema and pain due to inflammation and increased vascular permeability. Prompt recognition and treatment are essential to prevent serious complications.

Amyloidosis: This condition involves the deposition of amyloid proteins in various tissues, including the skin, which can cause non-pitting edema. It is often associated with other systemic symptoms such as weight loss and fatigue.
Sarcoidosis: Sarcoidosis is a multisystem disease that can cause edema due to granulomatous inflammation. It may be associated with other symptoms such as lung disease, skin lesions, and eye involvement.
Fabry Disease: This is a rare genetic disorder that can cause edema and pain in the lower extremities due to the accumulation of globotriaosylceramide. It is often associated with other systemic symptoms such as neuropathic pain and gastrointestinal disturbances.