Lymphedema: This condition is characterized by the abnormal accumulation of protein-rich fluid in the interstitial tissue, leading to non-pitting edema. It can be primary (congenital) or secondary (acquired) due to surgery, infection, or trauma.

Scleroderma: A chronic autoimmune disease that affects the skin and connective tissue, leading to fibrosis and non-pitting edema.
Lipedema: A condition characterized by the abnormal growth of fat cells in the legs, leading to non-pitting edema and pain.
Chronic Venous Insufficiency: A condition where the veins have problems returning blood to the heart, leading to non-pitting edema and skin changes.

Thyroid Dysfunction: Both hypothyroidism and hyperthyroidism can cause non-pitting edema, and it is crucial to rule out these conditions due to their potential impact on overall health.
Malignancy: Certain types of cancer, such as lymphoma or Kaposi's sarcoma, can cause non-pitting edema, and early detection is critical for treatment and prognosis.
Infection: Conditions like cellulitis or erysipelas can cause non-pitting edema, and prompt treatment is necessary to prevent complications.

Filarial Disease: Infections like elephantiasis can cause non-pitting edema, particularly in endemic areas.
Sjögren's Syndrome: An autoimmune disorder that can cause non-pitting edema, among other symptoms.
Pseudolymphoma: A rare condition that can cause non-pitting edema, often associated with other autoimmune disorders.
Fabry Disease: A genetic disorder that can cause non-pitting edema, among other systemic symptoms.