There are a good number of scientific markers of abnormalities in this disease. Here are just some of those
1- XMRV retrovirus in lab culture test.
Whittemore Petterson Institute-Judy Mikowitz

2- H2S metabolite Urine Test
De Meirleir

3 RNase L enzyme test
Dr. Robert Suhadolnik

4 Mitochondrial Failure
Shara Mhyll

5-Spectroscopic diagnosis of Chronic Fatigue Syndrome by visible and near-infrared spectroscopy in serum samples. Japanese researchers concluded that “Vis-NIR spectroscopy for sera combined with chemometrics analysis could provide a promising tool to objectively diagnose CFS.”
Fatigue Clinical Center in Osaka, Japan

6 Abnormal brain SPECT & PET scans
The Clinical and Scientific Basis of Myalgic Encephalomyelitis/CFS Dr. Byron Hyde

7Mitochondrial encephalopathy
Dr. Paul Cheney using Magnetic Resonance Spectroscopy

8Abnormal capillary flow due to high percentage of flat red blood cells instead of the normal discoid shaped red blood cells
Dr. Les Simpson, rheologist from New Zealand

9 Reduced red blood cell mass (RBC) ...is a critical hematological marker of ME-CIFDS-CFS.
(University of Miami)

10 Low circulating blood volume
Dr. David Bell, Lyndonville, New York

11 Abnormal bicycle ergometry test with gas analysis indicating immediate movement to anaerobic threshold in ME-CFIDS patients
Dr. Paul Cheney, who used this test for his disability reports

12 High percentage of patients with a viral load (HHV-6, EBV, cytomegalovirus) and/or Mycoplasma bacteria
Dr. Ablashi, Dr. Knox, Dr. Carrigan, Dr. Nicholson

13 Cardiac abnormalities due to viral invasion into the heart
Dr. Martin Lerner

14 Disregulated HPA axis
Dr. Mark Demitrack, Dr. Anthony Komaroff

15 Disregulated antiviral pathway
Dr. Suhadolnik

16 Head-up tilt test with haemodynamic instability
Dr. J. E. Naschitz

17 Abnormal T-helper 1/T-helper 2 Function Panel
Dr. Paul Cheney

18 Very low/impaired Natural Killer Cell Function
Dr. Paul Cheney, Dr. Kenny Demeirleir

19 Prolonged vasodilatory effect of acetylcholine on the microvasculature ...in addition to Peripheral Cholinergic illness in ME-CFIDS patients, Gulf War Illness, and illness following Organophosphate Exposure.
(Dr. Vance Spence)

20 Cardiomyopathy, liver failure, pancreatic cancer, brain tumors & renal disease ...reported after 40 years of research in Enteroviral and Toxin Mediated ME-CFIDS and Other Organ Pathologies.
(Dr. John Richardson)

21 Positive testing for Ciguatera Toxin Epitope
Dr. Yoshitsugi Hokama (Research funded by the National CFIDS/M.E. Foundation)

22 Neurally mediated hypotension

23 Abnormal “voyager” RNA (Preliminary studie)
Dr. Paul Cheney

24 5-HIAA, a metabolite of serotonin, may be present in elevated levels in ME-CFIDS patients
Georgetown University

25 Concentrations of a glucose metabolite in red blood cells

26 Differences in gene expression profiles
Dr. William Reeves in the cfids Chronicle

27 Excess nitric oxide activity

28 Blood hypercoagulability

29 Subclinical adrenal insufficiency
(present in about 2/3's of cases)

30 Reduced body temperature (can be caused by hypoadrenal +/- hypothyroid)

31 Magnesium deficiency