In March, we looked at differences between edema & lymphedema, overviewing various causes of swelling. In this post, we’ll take a deeper look at non-lymphedema causes of swelling (i.e. causes of edema). If you’re not a medical professional, this post might be a little challenging.
Non-lymphedema causes of swelling can be generalized (i.e. systemic, throughout the body) or it can be localized. We’re focusing on generalized edema. This is caused by a medical underlying condition & patients are not appropriate for Complete Decongestive Therapy (i.e. CDT) which is used in lymphedema treatment. In fact, treatment could cause harm because all fluid (including lymph) is returned to the heart. Moving large amounts of fluid increases cardiac burden & could also overwhelm kidney function. Additionally, because the reason for swelling is not mechanical insufficiency of the lymphatic system (which causes protein accumulation in the interstitium & lymphedema), CDT is not appropriate as it will not help. So, what are these causes of swelling which are not lymphedema?
- Increased hydrostatic pressure (increased venous pressure). In this case, fluid is not being returned to the heart as it should be & capillary venous pressure is increased. Fluid begins to back up in the feet & ankles, legs & sometimes the abdomen. A primary example of this would be right-sided congestive heart failure.1
- Increased fluid osmotic pressure in the interstitium. This occurs because of increased capillary permeability (increased arteriolar dilation) which allows greater amounts of protein to leave the blood. An example of this would be a thyroid disorder (i.e. Hypothyroidism).2
- Decreased plasma (blood) osmotic pressure. In this case the body is losing too much protein. Kidney failure & malnutrition would be prime examples of this.3,4
- Hyponatremia (sodium retention). Sodium is the most abundant electrolyte in extracellular fluids & is the major determining factor of extracellular fluid osmotic pressure. Diarrhea, vomiting, heart failure & other causes can be reasons the body retains salt.5,6
1Kumar, V., Abbas, A., Aster, J. (2013). Robbins Basic Pathology (9th ed.), location 3972. Pennsylvania: Elsevier Saunders.
2Kumar, V., Abbas, A., Aster, J. (2013). Robbins Basic Pathology (9th ed.), location 3872. Pennsylvania: Elsevier Saunders.
3Kumar, V., Abbas, A., Aster, J. (2013). Robbins Basic Pathology (9th ed.), location 3860. Pennsylvania: Elsevier Saunders.
4Tortora, G., Grabowski, S. (1996). Principles of Anatomy & Physiology (8th ed.), p. 619. New York: HarperCollins College Publishers.
5Kumar, V., Abbas, A., Aster, J. (2013). Robbins Basic Pathology (9th ed.), location 4009. Pennsylvania: Elsevier Saunders.
6Tortora, G., Grabowski, S. (1996). Principles of Anatomy & Physiology (8th ed.), p. 838. New York: HarperCollins College Publishers.