Univ.-Prof. Dr. Tim Hucho
Rebecca Dinnendahl, M.Sc., PhDc
Lipedema Foundation’s 2022 First Look Report [1] highlighted that individuals with Lipedema reported persistent sensory discomfort and flaring pain associated with the condition. Based on responses from over 500 individuals provided through the Lipedema Foundation Registry [2], the average daily pain intensity rates at 5 on a 10-point scale, with only 4% of respondents reporting no pain on a typical day. This sensory discomfort and pain, which is supported by both published reports and patient anecdotes, is often questioned or dismissed by medical personnel.
In 2022, Lipedema Foundation sponsored research by Prof. Dr. Tim Hucho and Rebecca Dinnendahl, PhDc in Germany. The goal of this recently published research study was to make such reports of pain in part objectifiable by measuring the sensitivity to a variety of stimuli such as warmth, cold, touch, painful heat, painful cold, pressure pain, and vibration. Their findings suggest a heightened sensitivity to pressure pain, a reduction in sensitivity to vibration, and a completely normal response for all other tested sensations. These results align nicely with anecdotal reports we hear from women with Lipedema. This may relieve many from the anxiety of explaining the sensation they experience to an often critical audience. Furthermore, the use of such measurements may support the development of an objective diagnostic criterion that could be used even in early-onset Lipedema.
The Lipedema Foundation had the pleasure of interviewing Dr. Tim Hucho, the Principal Investigator, and neuroscientist Rebecca Dinnendahl, first author on the publication and lead scientist of the study, to discuss what pain is and why this research matters for individuals with Lipedema, clinicians, and the research community. Read more to hear their perspective on pain in general, on the research outcomes, their thoughts on working with the Lipedema population, and future implications for enhancing the early diagnosis of Lipedema – specifically an explanation of the potential of using sensory testing as an accessible diagnostic tool going forward.
What is pain?
Tim Hucho (TH): Defining pain is challenging for researchers, and the definition continues to evolve. The International Association for the Study of Pain (IASP) currently defines pain as “an unpleasant sensory and emotional experience…” Strongly simpliifying, one might say, “If you experience something as pain, it is pain.” The IASP emphasizes this by stating, “A person’s report of any experience as pain should be respected.”
This highlights several important aspects of pain. First, pain is always a combination of sensation and emotion—it’s never just one or the other. Second, unlike seeing or hearing, where stimuli are directly represented in the brain, pain is an experience shaped by sensations and emotions, resulting from complex computations and modulations within the body. Third, since pain is deeply personal, each person’s pain is unique, and only the individual experiencing it can truly understand it.
The IASP also notes, “Through their life experiences, individuals learn the concept of pain.” For example, the feeling of a heavy or hurting leg varies depending on the setting, time of day, or if it interferes with an activity the individual really wants or needs to do. There is no single type of pain; it changes with each situation. As a result, each of us has multiple “pains,” and these experiences can shift based on circumstances and what we’ve learned. This complexity can be overwhelming, but it also presents opportunities.
The multifaceted nature of pain means there isn’t just one solution to managing it. One’s own “pain experience” is the result of ongoing processes that constantly compute and modulate sensations, feelings, emotions, surroundings, and experiences. As the expert of your own pain, there are many ways to explore what might alleviate it in different situations. Just as we know what makes pain worse, we can also discover what helps minimize it.
Rebecca Dinnendahl (RD): Tim and I, along with the scientific community, are working to understand the complex and changeable process of pain, particularly in individuals with Lipedema. Through our research, we aim to offer guidance to help each person find what best supports them. Pain is a key symptom in the German guidelines for Lipedema, so it might seem straightforward to simply measure it. But as Tim noted, pain experiences are difficult to define, and current methods can't fully capture pain as a specific measurement. A number between 0 and 10 doesn’t reflect the full mix of sensations, emotions, learned behaviors, and communication nuances that influence the pain experience.
In our experience, less is more. Instead of trying to measure "pain" as a whole, we focus on measuring specific aspects of pain that individuals with Lipedema experience at a given moment. For instance, we measure sensitivity to single sensations like temperature or pressure. While this might seem limited compared to the broader concept of pain, it allows us to clearly demonstrate that pressure sensitivity is a real symptom of Lipedema. To do this, we use a widely recognized scientific method called Quantitative Sensory Testing (QST).
What is Quantitative Sensory Testing (QST), and why was it chosen for this study?
RD: Quantitative Sensory Testing (QST), conducted according to the German Research Network on Neuropathic Pain (DFNS) protocol, is a comprehensive and scientifically standardized method developed in Germany and used in the United States. It assesses a person's sensory status through seven different tests across thirteen parameters, including warmth, cold, touch sensitivity, heat pain, cold pain, pressure pain, and vibration sensitivity.
We measure sensory thresholds by starting with an undetectable stimulus, gradually increasing its strength until the person being tested first feels it, and then again when it becomes painful. The measurement, such as temperature or stimulus strength, is then recorded from the testing instrument. This process is similar to a traditional hearing test, where sound is gradually increased until the person detects it. By repeating this process multiple times, always starting with an undetectable level, we establish the average sensory threshold for each test.
TH: QST focuses on individual components of pain, offering more specific understandability than the traditional 0-10 pain scale or even a yes/no question of pain, which can be influenced by various factors, including sensory experiences, emotions, memories, motivations, and even the dynamics of who is asking or answering the question. The 0-10 scale is an important tool, but often difficult to interpret or compare due to these complexities.
In contrast, QST reduces this unreliability and improves comparability through several key aspects:
The measurements are taken by personnel specifically trained in QST, rather than by the individual being tested, who, from a scientific standpoint, is not a perfectly reliable measurement "device."
The mastery of the QST method is ensured by comparing each measurement, particularly the thresholds at the hand (as a control), against thousands of controls in the DFNS database.
Sensory thresholds are measured individually, rather than combining all senses into a single question like “Rate your pain on a scale from 0 to 10.”
During the test, the threshold "numbers" remain invisible to the person being tested, allowing them to focus fully on the test.
The threshold is measured multiple times in succession to establish a reliable average value.
Pain with Lipedema is typically felt in the affected legs and arms, not the hands. Therefore, using "control" measurements on the hand helps establish the individual's "normal" threshold, which can then be compared with the threshold in the affected area.
Comparing the individual's measurements with thousands of past measurements in the QST database may enable us to directly use these measurements as a factor in supporting potential diagnostics.
The results of this study show that the sensitivity (pain) individuals with Lipedema report is real and measurable, and not just psychological. Can you elaborate on this?
TH: Many factors contribute to the experience of pain, including how sensitive the nerves are to potentially painful stimuli, the activity of the immune system (such as aching joints during a fever), physical stress after a long day, and even emotional and social factors. QST measurements focus almost exclusively on sensory nerves, thereby eliminating many of these other influences.
Our initial QST results offer some good news—overall sensations in individuals with Lipedema appear normal across most dimensions. The exceptions we found in this study are a heightened pressure sensitivity (pain) and reduced vibration sensitivity in the affected legs. When testing on the control area (hands), values were “normal” compared to unaffected controls. This study provides objective and measurable evidence that the heightened pressure sensitivity in the affected legs, as long reported by women with Lipedema, is real.
RD: Previous reports have hypothesized various possible causes for Lipedema pain. One study strongly suggested that Lipedema pain is predominantly psychosomatic, meaning it might be generated mostly by the individual’s psyche with little involvement of sensory neurons in the affected area. Since pain always involves both sensory and emotional factors, we also wanted to test this hypothesis. We conducted an extensive questionnaire-based analysis of psychological aspects like anxiety, stress, and depression. In our tested population, all these measurements were within a fully normal range compared to controls, indicating that a purely psychosomatic cause for the heightened pressure sensitivity in the legs is highly unlikely. While our data, supported by other studies, shows that Lipedema does take a psychological toll, the burden is not clinically significant enough to be the primary cause for the reported pain we observed here.
How does this research address the frustration of Lipedema patients whose pain has been minimized or dismissed by medical professionals?
TH: Lipedema has been recognized in medical literature for 80 years, with heightened sensitivity and pain frequently reported, yet patients continue to report that the pain is often not taken seriously by medical professionals. Our results may help change this, as the pressure pain threshold is now measurable. Women with Lipedema in this study expressed relief, knowing they no longer have to argue that the pain isn’t “just in their head.”
However, we must ask: Does Lipedema always equal pain? For untreated women, the answer currently seems to be yes most often, but we don’t know for sure. There may be cases where pain is less obvious, absent, or even unrecognized by the woman herself. The full picture is still emerging, and it should be described by the women with Lipedema.
Ultimately, wouldn’t it be great to separate Lipedema from pain? Ideally, we could find ways to manage or eliminate the pain so that it becomes a negligible part of Lipedema. But to move in this direction, we must start by accepting the many reports of pain and sensory changes. Once we can objectively establish aspects of pain, we can work on understanding and alleviating the pain. Sensory measurements are a crucial starting point for those living with Lipedema and for scientists and practitioners.
Can you elaborate on the difference between pain as a psychological experience versus being physically motivated?
TH: Pain is a tricky thing and many factors play into it, including both sensory and emotional components, among others. Thus, I would strongly encourage both people with pain and clinicians to stop thinking of pain in the pure and separated categories of somatic (physical) versus psychosomatic (in the head). As stated in the definition, pain is always both. From a physical standpoint, patients should have clinicians check the body for possible causes of pain and for aggravating factors. For example, tissue inflammation or vascular and lymphatic causes, orthopedic issues, or even medicines may be important factors of the pain. If that is the case, these issues can be targeted by clinical or other therapeutic means. Learning how to modulate pain experiences by regulating one’s own emotions and avoiding things that can trigger or aggravate painful feelings can also help.
It's interesting to note that both physical and psychological aspects are often viewed primarily through the lens of pathology. However, they are fundamentally strong positive resources that enable individuals to navigate a complex world. Many of these responses were shaped by evolution in environments very different from the ones we live in today. For instance, in the Stone Age, withdrawing from society due to physical pain may have been a protective measure, signaling the need for rest and recovery. But in our modern times, such behavior may no longer serve us as well.
Therefore, while it is often overlooked, it is crucial to understand what can alleviate these situations. It’s equally important to explore our own actions, desires, hobbies, and social interactions. Even when they aren’t directly related to pain, these aspects of our life can be valuable resources. In fact, many women with Lipedema today have become experts in managing their condition. By sharing their experiences, they are not only helping themselves but also providing valuable support to others. [Check out the treatment resources Lipedema Foundation has compiled with treatments that patients have reported to help manage their symptoms.
What would need to happen for QST to be used as a diagnostic tool for Lipedema?
RD: QST is an advanced tool for measuring aspects of pain, and as such, it is expensive, requires substantial training, and takes considerable time to perform the measurements. This means that the full QST method may not be practical for use in every clinical setting. However, it appears that we may not need to use the entire method in the case of Lipedema.
In this study, we initially tested 13 parameters on both the hand (control) and an affected leg, which took about 1 to 1.5 hours to complete. However, we discovered that only two of these parameters showed significant changes in the tested population. In fact, just measuring these two parameters at the hand and leg was enough to differentiate women with and without Lipedema. Testing just these two parameters is affordable, easy to train for, and takes only about 10 minutes.
However, let’s not jump to conclusions—this is science, after all! We have "only" the initial evidence suggesting that this may be possible. The most important next step is to replicate this in a larger, independent study. Scientific results are always just models or hypotheses. The validity of these models is determined by continuous retesting and application. This long process is what needs to begin now.
What are the next steps for this research?
TH: As scientists, we are cautious in interpreting such data. Our measurements show that participants in this study with Lipedema have heightened sensitivity to pressure pain and reduced vibration sensitivity in the leg, with other aspects appearing normal. This suggests that we may now have a measurable aspect of pain in people with Lipedema. It's exciting that, alongside clinical diagnosis, just two simple measurements—pressure pain and vibration detection—might reliably indicate the presence of Lipedema. However, this is only a preliminary step, and much more work is needed to confirm these findings.
The next critical step is to replicate this study in a larger cohort, which we are currently doing across 10 different Lipedema centers. The published study focused on women of average weight, so for future iterations we are also expanding the study to include women in the middle and higher weight ranges, and early data is promising. Additionally, understanding the underlying cellular and molecular mechanisms of pain in Lipedema is essential. Rebecca has conducted many experiments in this area, though it will likely be a lengthy process. This research could also eventually lead to pharmacological studies aimed at mitigating pain.
Finally, research into the factors affecting Lipedema pain is still in its early stages. To explore this further, we and our colleagues from the pain center have established a specialized counseling service for women with Lipedema and pain. This will help us understand more about the condition and how current treatments might alleviate some of its symptoms, while also learning from the experiences of these women.
How does the Lipedema patient’s experience factor into this and future research?
RD: As newcomers to the Lipedema field, we’ve been warmly welcomed. Typically, scientists spend most of their time in the lab, but talking to women directly affected by this disease has been invaluable, especially for me as a neuroscientist with a background in nursing. When women with Lipedema share their personal stories and details about how they cope and make a difference for themselves, it helps us form hypotheses for further research. Hearing directly from these women shows us what truly matters to them and where we need to focus our research efforts.
TH: We are extremely thankful to the women with Lipedema who shared their experiences, as their guidance is essential for our research. They help define the questions we address with our scientific tools. We are also deeply grateful to the women, both with and without Lipedema, who participate in these studies. The women we've met are impressively strong, demonstrating incredible grit in facing their situation. Their achievements and the strong communities they build are both stunning and inspiring. It’s often emotional and deeply encouraging for us to see the relief on their faces when we present data that validates their pain as real and legitimate.
We are also immensely grateful to the Lipedema Foundation. Their support, both in funding and in providing invaluable knowledge and networks, has been crucial to our progress. Talking to them greatly helps us shape our research to target the aspects most needed by the community.
How can patients get involved?
As Tim and Rebecca emphasized, patient involvement plays a crucial role in shaping research priorities and guiding future studies. The Lipedema Foundation offers various avenues for patients to engage:
Join the Lipedema Foundation Registry to contribute to ongoing research efforts.
Stay updated on the evolving landscape of Lipedema research by exploring Legato Library, the comprehensive research library curated by the Lipedema Foundation.
Find and participate in clinical research studies to support your care and advance medical knowledge using Lipedema Foundation’s LEGWORK clinical study locator tool.
Utilize the Patient Self-Advocacy Guide to navigate your Lipedema journey effectively.
Additional References for the Lipedema Community
Patient stories inspire our mission and drive our commitment to define, diagnose, and develop treatments for Lipedema. Amplify your own story by sharing on your social media channels using the hashtags #Lipedema and #Lipedemaawareness.
Explore a range of Lipedema treatment options for managing symptoms, and inform us about any effective treatments we may have overlooked.
Educate healthcare providers by sharing the Clinician’s Guide to Lipedema and directing them to our extensive Clinician Resources.
Encourage physical, occupational, and massage therapy professionals to join the Provider Directory to help other Lipedema patients find specialized care.