What causes large fluid pockets under the skin?

Large fluid pockets under the skin, known as seromas or edema, can be caused by various factors, including injury or trauma, inflammation, surgery, or underlying medical conditions such as heart, liver, or kidney disease. These pockets form when fluid leaks from blood vessels into surrounding tissues, often due to increased pressure or inflammation. Infections and allergic reactions can also contribute to fluid accumulation. Treatment typically involves addressing the underlying cause and may include draining the fluid or managing the condition with medications.