There are many proposed diseases and diagnoses that are rejected by mainstream medical consensus and are associated with pseudoscience.
[1] Other conditions may be rejected or contested by orthodox medicine, but are not necessarily associated with pseudoscience.
Diagnostic criteria for some of these conditions may be vague, over-inclusive, or otherwise ill-defined.
Although the evidence for the disease may be contested or lacking, the justification for these diagnoses is nevertheless empirical and therefore amenable to scientific investigation, at least in theory.
In some cases, patients are exhibiting genuine signs and symptoms but the explanation or diagnosis for their distress is disputed or inaccurate.