Anorexia nervosa is a psychological condition distinguished by unhealthy weight-loss behaviors due to the perception and fear of being overweight. It is characterized as an eating disorder because it commonly manifests in compulsive self-starvation, often resulting in extreme, yet typically unacknowledged, weight loss. Despite its psychological nature, anorexia nervosa is frequently accompanied by physical symptoms such as edema. Often emerging due to protein deficiency caused by anorexic behaviors, edema can become a significant complicating factor in treatment by giving the patient a subjective impression of weight gain. The case patient, Amanda, appears to present a typical case of anorexia nervosa. Although her BMI is under 14, she is convinced that she is overweight because her clothes feel too tight, and her hands and feet are swollen. According to her nurse, she suffers from a deficiency of a particular type of protein in her blood, which can be remedied with a healthy diet. Amanda could remove the edema by following dietary prescriptions, making it easier for her and her care team to treat the underlying eating disorder.
Edema is the accumulation of excess fluid in a specific area of the body, causing swelling. It occurs when the balance between the “forces that determine the distribution of fluid between the vascular and interstitial compartments” (Banasik & Copstead, 2018, p. 528), namely hydrostatic and oncotic pressures, become disrupted. Hypoproteinemia is a frequent cause of this disruption due to the importance of proteins in maintaining oncotic pressure in the blood vessels (Lieberman & Peet, 2018). It seems probable that the protein Amanda’s nurse referred to is serum albumin. As the main serum protein, albumin contributes up to 80% of the plasma’s oncotic pressure (Lieberman & Peet, 2018, p. 918). Although other plasma proteins can compensate for its deficit in part, the lack of albumin regularly leads to moderate edema (Lieberman & Peet, 2018). Reduced oncotic pressure due to insufficient albumin allows more plasma water to enter the interstitial space, causing it to expand and produce surface swelling. Conversely, an albumin-rich diet would help Amanda restore the balance between pressures and keep fluid out of the blood vessel.
In addition to potentially originating from multiple causes, edema can be differentiated into pitting and non-pitting varieties. As can be seen from their names, the principal difference between those conditions lies in how they respond to pressure. The brief application of pressure on pitting edema would result in a lasting indentation that only fills in gradually (Chaar, 2018). The flexibility of pitting edema is due to the presence of excessive fluid. No such indentation occurs in non-pitting edema, as it is influenced by other factors in addition to fluid build-up. Those factors include the concentration of fat cells in lipedema, the deposition of mucopolysaccharides in the dermis in myxedema, or a lymph blockage in lymphedema (Chaar, 2018). As a result, checking for pitting edema can be useful in the differential diagnoses of those diseases. However, those conditions can also underlie pitting edema, as they all present with the accumulation of fluid within tissues. Establishing the possibility of those dangerous conditions would help set the priorities in Amanda’s treatment.
Due to her considerable weight loss, Amanda is generally confined to bed rest and forced to rely on a wheelchair to get around the ward. Although necessitated by her poor health, this restriction on Amanda’s mobility may pose a further complication for her treatment. Prolonged standing or sitting can result in dependent edema, as gravity causes venous pooling of fluid in the lower parts of the patient’s body (Chaar, 2018). Lack of physical activity makes the retention of fluid in limbs more likely. Since Amanda already suffers from swelling in her feet, the additional influence of gravity may be expected to exacerbate this effect. The edematous tissues in her hands are likely to be affected to a lesser extent as they are higher up. However, dependent edema may be partly remedied by the rebalancing that occurs during bed rest. Muscle compression, exercise, and elevation of affected areas through cushions and similar means would provide further relief.
Edema is both a common symptom and a complicating factor in anorexia nervosa. Undereating and other unhealthy weight-loss behaviors connected to anorexia are likely to result in protein deficiency. Proteins such as serum albumin are essential for sustaining the oncotic pressure that counteracts hydrostatic pressure and draws fluids into blood vessels. If the supply of albumin or other proteins is disrupted, water from the capillaries will begin to build up in nearby interstitial compartments, causing them to expand and produce visible swelling. In patients who are already irrationally alarmed about weight gain, the swelling is likely to reinforce their unhealthy tendencies. Dietary adjustments can help restore albumin levels and reduce edema, negating its exacerbating effect on anorexia. Checking for pitting edema can help healthcare providers determine whether the swelling is caused primarily by fluid build-up, allowing them to make a differential diagnosis. A patient’s reliance on a wheelchair as a mode of transport is likely to pose a further complication in the form of dependent edema, in which gravity causes additional fluid build-up.
Banasik, J L. & Copstead L-E. C. (2018). Pathophysiology. (6th ed.). Saunders.
Chaar, C. I. O. (Ed.). (2018). Current management of venous diseases. Springer International Publishing.
Lieberman, M., & Peet, A. (2018). Marks’ basic medical biochemistry: A clinical approach. (5th ed.). Wolters Kluwer.