We know that the disease lipedema involves an impairment of fat cell distribution and deposition (hyperplasia or hyperproliferation) and that this usually occurs symmetrically in the body, so in both legs (and sometimes both arms). You might hear about fat cells being called by their clinical name, adipocytes.
But how does lipedema become a fluid problem in later stages? Well, the research is still rather young, and the causes can be multi-factorial, but let’s look at some ideas:
One thought is that these accumulated overgrowths of fat cells within the tissues cause the lymphatic structures to be essentially squashed in some areas. According to a case report put out by the Annals of Rehabilitation Medicine in 2011, pressure from the fat cells on lymph collectors that live in the superficial layers, particularly, means that those vessels can’t do their job of absorbing lymph fluid from the tissues and carrying it out back toward the heart. And this squashing can lead to damage of the lymphatic vessels themselves.
This squashing pressure problem on the vessels only gets worse later on when the fat cells themselves become waterlogged and enlarged (also called hypertrophic). Now we’ve not only got too many fat cells in the tissue, the cells themselves are excessively large!
It was also seen in a paper by Allen, Schwartz, and Herbst in Women’s Health Report in 2020 that the skin in the thigh region of women with lipedema showed more space between the collagen fibers than in the skin of the control group, which gives more room for that lymph fluid to accumulate. (Interestingly the abdominal skin did not show that increased space between collagen fibers, only in the thigh.)
In that same paper, the authors wrote that they found more abnormal or “leaky vessels” in the sample skin of women with lipedema (particularly early stage and non-obese women) and they believe that women with lipedema may have increased vessel leakiness due to decreased collagen in the walls of the vessels.
It’s been suggested in a paper in the Obesity research journal in 2022 that in the lower extremities in earlier stages of lipedema, the lymphatic system is often able to handle the increased fluid accumulation, and that it was shown that in some cases, the lymphatic system in people with early-stage lipedema worked at a higher capacity than with a control group! BUT all that extra work can stretch out the lymphatic vessels, rendering them unable to do their job well after all that dilation and wear and tear, and that can be part of what causes things to progress to later-stage lipedema becoming a fluid problem, or lipo-lymphedema.
Speaking of progression, a recent review paper published in the International Journal of Molecular Sciences in 2022 highlights how lymphedema and lipedema progress in opposite directions when it comes to fluid, fibrosis, and fat:
Lymphedema starts off as an excess fluid problem, which then turns to inflammation and fibrosis as it progresses, and then ends up as an excess fat problem as the body is triggered to lay down extra adipocytes.
Lipedema starts off as an excess fat problem, which then leads to inflammation and fibrosis, and then ends up as an excess fluid problem in later stages as breakdowns in the lymphatic system and its functioning start occurring.
So we can see the similarities between these two conditions and how they overlap but also how they progress in opposite ways.
There is still so much to learn about lipedema, but little by little we’re building a bank of research (hallelujah!). And the more research that gets compiled, the more guidance we have on how to treat this chronic disease in order to improve quality of life for those living with lipedema.
Shin et al, 2011, B.W. Shin, Y. J. Sim, H.J. Jeong, G. C. Kim. “Lipedema, a rare disease” Ann. Rehabil. Med., 35 (2011) pp.922-927
Allen, Marisol, Michael Schwartz, and Karen L Herbst. “Interstitial Fluid in Lipedema and Control Skin” Womens Health Rep (New Rochelle). 2020; 1(1): 480–487.
Rasmussen, John C, Melissa B Aldrich, Caroline E Fife, Karen L Herbst, Eva M Sevick-Muraca. Lymphatic function and anatomy in early stages of lipedema. Obesity (Silver Spring). 2022 Jul;30(7):1391-1400.
Bailey H. Duhon,Thien T. Phan, Shannon L. Taylor, Rachelle L. Crescenzi, and Joseph M. Rutkowski Current Mechanistic Understandings of Lymphedema and Lipedema: Tales of Fluid, Fat, and Fibrosis Int J Mol Sci. 2022 Jun; 23(12): 6621.