Doctor proposes Long COVID is a cluster of overlapping biological subtypes

A Plano, Texas physician is pushing a new framework that says Long COVID should be understood as a broad umbrella of overlapping mechanisms rather than one single disease cause. The model could change how researchers design studies, and how clinicians identify which patients are most likely to benefit from targeted treatment.

Why it matters: - The framework challenges a common assumption in Long COVID research: that one cause will explain every patient’s symptoms. - Dr. Robert Groysman’s model argues that better subgrouping could improve study results, avoid diluted trials, and make mechanism-targeted treatment more effective. - The idea also addresses a communication problem, where a finding in one patient subset can be mistaken for a universal explanation.

What happened: - Dr. Robert Groysman introduced a three-part framework that treats Long COVID as a biologically heterogeneous condition. - The model uses an umbrella-and-puzzle approach to separate the broad Long COVID diagnosis from the different mechanisms driving symptoms in different patients. - The framework was presented in connection with a published paper in Frontiers in Medicine, titled “Long COVID as a network disorder,” with DOI 10.3389/fmed.2026.1841690. - Two related manuscripts are in development.

The details: - The framework places Long COVID under a broad umbrella that includes multiple overlapping biological drivers. - Those drivers include dysautonomia, mitochondrial dysfunction, endothelial dysfunction, immune activation, viral persistence or reactivation, mast cell activation, gut dysbiosis, hormonal disruption, small fiber neuropathy, and other interacting pathways. - One patient may primarily have dysautonomia and sympathetic overdrive. - Another patient may have endothelial dysfunction and microvascular impairment. - Another patient may have immune activation or viral reactivation. - Many patients may have several active mechanisms at the same time. - The model explains why patients can share the same diagnosis while having different symptoms, triggers, lab findings, and treatment responses. - Dr. Groysman said the problem is not that researchers are wrong, but that subset findings are often treated as if they apply to all Long COVID. - Many studies focus on a single pathway, including viral persistence, autoimmunity, microclots, immune dysregulation, autonomic dysfunction, or mitochondrial impairment. - Those studies can still be valuable because they may identify an important mechanism in a biologically selected subset. - A treatment aimed at endothelial dysfunction may fail in a mixed population if only a subset has that problem. - A mitochondrial treatment may look weak if most enrolled patients do not have a dominant energy-recovery problem. - A dysautonomia treatment may be obscured when patients with POTS and sympathetic overdrive are grouped with patients whose drivers are different. - The framework calls for enriched biological endotypes instead of enrolling patients only because they carry the Long COVID label. - An endothelial study should enrich for vascular, clotting, or capillary markers. - A dysautonomia study should enrich for orthostatic intolerance, POTS physiology, or autonomic testing abnormalities. - A mitochondrial study should enrich for post-exertional energy failure and delayed recovery. - Dr. Groysman also uses a “Long COVID Car” model to explain why patients can look similar but need different treatments. - In that model, the driver represents the mechanism steering the illness. - The passenger, back seat, and trunk represent other findings that may be present without currently driving symptoms. - Fatigue, brain fog, dizziness, anxiety, and post-exertional crashes can appear across patients even when different mechanisms are at the wheel. - The framework also describes Long COVID as a network disorder, not a single switch. - Dysautonomia can affect gut motility. - Gut dysbiosis can amplify immune activation. - Immune activation can affect the endothelium. - Endothelial dysfunction can impair oxygen delivery. - Sympathetic overdrive can keep the body stuck in a chronic alarm state.

Between the lines: - The framework is as much about interpretation as biology: a study finding may be real without being universal. - That distinction could matter for patients who have been frustrated by broad conclusions that do not match their own symptom pattern. - The model also gives researchers a sharper way to ask whether they are studying Long COVID broadly or a biologically selected subgroup. - Dr. Groysman developed the framework to help patients and clinicians connect symptoms to underlying mechanisms.

What's next: - Dr. Groysman says future research should move toward mechanism-based classification rather than broad-label enrollment. - The model suggests the key research question should shift from whether a treatment works for all Long COVID patients to which endotype a treatment is designed for. - The framework is intended to help clinicians interpret new studies more carefully and identify patients most likely to respond to targeted therapy.

The bottom line: - Long COVID may not have one cause. The framework argues it is better understood as a mix of overlapping biological subtypes that need different research strategies and different treatments. - The COVID Institute in Plano, Texas, specializes in Long COVID and post-viral condition diagnosis and treatment under Dr. Groysman. - The practice says it uses a six-mechanism framework addressing dysautonomia, mitochondrial dysfunction, endothelial damage, gut dysbiosis, mast cell activation and hormone imbalance. - Media inquiries: press@longcovidfamily.com - More information is available through Dr. Groysman’s social channels: Facebook, Instagram, X, YouTube, and LinkedIn.