Why Am I So Tired When My Blood Work Is Normal? What Standard Testing Misses — What the Host Capacity Model says is actually happening

The Host Capacity Model is a systems-biology framework that approaches chronic illness from the layer where conventional labs are silent. The framework is described in full at the Host Capacity Model page . The relevant aspect for this article is the layer where the lesion typically lives in patients with normal labs and persistent symptoms. The thesis is direct. Most chronic illness in patients with normal conventional labs is a cellular bioenergetic problem, an autonomic regulatory problem, a gut barrier and microbial community problem, or some combination of all three. None of these problems are captured by the standard panel. All of them produce the symptoms that the patient experiences. The gap between feeling terrible and testing normal is the gap between cellular function (where the lesion is) and serum concentrations of acute-disease markers (where the test is). Several specific mechanisms operate at this layer. Each is well-established in the primary literature. None is captured by standard labs. Together they account for most of what produces chronic illness in the absence of frank disease. Mechanism 1: Cellular bioenergetic compromise Cells generate ATP through a sequence that involves substrate transport, intracellular processing, mitochondrial oxidation, and electron transport chain function. Each step can be intact while a downstream step is compromised. A cell ca