Edema

In medicine, edema is "abnormal fluid accumulation in tissues or body cavities. Most cases of edema are present under the skin in subcutaneous tissue."

Similar terms are:

• Angioedema is "swelling involving the deep dermis, subcutaneous, or submucosal tissues, representing localized edema. Angioedema often occurs in the face, lips, tongue, and larynx."
• Lymphedema is "edema due to obstruction of lymph vessels or disorders of the lymph nodes.
• Myxedema is a "condition characterized by a dry, waxy type of swelling (edema) with abnormal deposits of mucopolysaccharides in the skin and other tissues. It is caused by a deficiency of thyroid hormones. The skin becomes puffy around the eyes and on the cheeks. The face is dull and expressionless with thickened nose and lips."

Extreme cases of edema are called anasarca.

Etiology/cause

• Hydrostatic due to heart failure or venous insufficiency.
• Cirrhosis
• Protein-energy malnutrition including Kwashiorkor and marasmus
• Acute kidney injury or chronic kidney disease
• Medications such as vasodilator agents used for hypertension may cause edema by stimulating sodium reabsorption.
• Obesity may by associated with both lymphedema and edema. 75% of morbidly obese patients (body mass index >40) may have lymphedema. Obesity may be associated with edema due to obstructive sleep apnea and secondary pulmonary hypertension.

Diagnosis

Physical examination

On physical examination, fast recovery of pitting is associated with lower serum albumin levels. Fast recovery within 2-3 seconds, is more sensitive than specific at detecting hypoalbuminemia. Presumably this is related to the viscosity of the interstitial fluid thus hypoalbuminemic interstitial fluid can reform more quickly.