Heart Failure: This is a common cause of swelling (edema) in the hands and legs, particularly in older adults or those with a history of heart disease. The swelling is due to the heart's inability to pump blood effectively, leading to fluid buildup in the body.

Kidney Disease: Conditions such as nephrotic syndrome or chronic kidney disease can cause edema due to the kidneys' reduced ability to filter and remove waste and excess fluids from the body.
Liver Disease: Cirrhosis and other liver conditions can lead to edema, especially in the legs, due to the liver's decreased ability to metabolize proteins and the subsequent buildup of fluid.
Lymphedema: A condition characterized by the abnormal collection of protein-rich fluid in the interstitial tissue, leading to swelling of one or more extremities.

Deep Vein Thrombosis (DVT): Although less common as a cause of bilateral swelling, DVT can cause significant swelling in one leg and is a medical emergency due to the risk of pulmonary embolism.
Sepsis: In severe cases, sepsis can cause widespread edema due to increased vascular permeability and can be life-threatening if not promptly treated.
Severe Hypothyroidism (Myxedema): A condition that can cause non-pitting edema, particularly of the hands, feet, and face, and is critical to diagnose due to its impact on multiple bodily systems.

Sarcoidosis: A condition that can cause edema among other symptoms due to the formation of granulomas in various parts of the body, including the lungs, skin, and eyes.
Amyloidosis: A group of diseases characterized by the accumulation of amyloid (a particular type of protein) in various organs, which can lead to edema among other symptoms.
Fabry Disease: A rare genetic disorder that can cause edema, among other symptoms, due to the buildup of a particular type of fat in the body's cells.