ME/CFS often appears similar to several different and distinct illnesses. The following section will assist patients and health care providers distinguish other illnesses from ME/CFS. It is critical not to misdiagnose ME/CFS as another illness, nor diagnose another illness as ME/CFS.

See pages 14-16 of the ME/CFS: A Primer for Clinical Practitioners for an overview of what clinicians should be considering as differential diagnoses. The most common conditions confused with ME/CFS are listed below, with descriptions in "patient" language. 


ME/CFS and Fibromyalgia

ME/CFS and Fibromyalgia


ME/CFS and Multiple Sclerosis

ME/CFS and Multiple Sclerosis (MS)

National Multiple Sclerosis Society


ME/CFS and Chronic Lyme Disease

American Lyme Disease Foundation —ALDF is active in media outreach, education (medical and public) and research programs.  

A Personal Journey into Lyme Disease

Book review of Cure Unknown: Inside the Lyme Disease Epidemic by Pamela Weintraub

Chronic Lyme Disease Diagnosis stirs Controversy

Dr. Sam Donta: The Interface of Chronic Lyme Disease, CFS and FM

Lyme disease and other tick-borne illnesses on the rise!

Lyme Disease Association (LDA)— Organization dedicated to Lyme Disease education, prevention, and the raising of research funds.Various educational brochures and primers available at their website.

Lyme Disease Network (LymeNET)—Comprehensive website offering online library, listing of national support groups, and a user forum.

ME/CFS and Chronic Lyme Disease

Sturbridge Lyme Awareness of Massachusetts (SLAM)

Symptoms Common to Lyme Disease and CFIDS 


ME/CFS and Chiari Malformation

CFS/FM and Chiari Malformation Surgery

ME/CFS and Chiari Malformation 


ME/CFS and Psychiatric Disorders

See pages 16-17 of the ME/CFS: A Primer for Clinical Practitioners

1994 Definition and Overlap with Psychiatric Conditions

CFS Distinguished from Depression in Boston-based Study

Dr. Komaroff Publishes Article Demonstrating that CFIDS Is A Physical and Not A Psychiatric Illness

ME/CFS and Psychiatric Disorders

On the Morbid Fascination with Psychiatric Morbidity by Dr. Alan Gurwitt, a pioneer ME/CFS psychiatrist, who clearly explains the distinctions between ME/CFS and psychiatric illnesses.


ME/CFS and Multiple Chemical Sensitivities

CFIDS and Multiple Chemical Sensitivities

American Academy of Environmental Medicine—A physician's organization—you can search for members who practice environmental medicine in your area.

Chemical Injury Information Network—Provides information and referral to members; publishes a monthly newsletter. Maintains a library on chemical injury.

Human Ecology Action League, Inc.—Information clearinghouse with chapters and support groups around the country.

Massachusetts Association for the Chemically Injured (MACI)—Information, referral and support for people with MCS. Also holds monthly meetings and publishes a newsletter.

Multiple Chemical Sensitivities Referrals and Resources—A wealth of information for patients and health care providers.

National Center for Environmental Health Strategies—Focuses on initiating change and empowering the public with hard data, such as medical, legal, and policy information. Provides information on gaining accommodations at work and school.


ME/CFS and Mitochondrial Disease

Mitochondrial Dysfunction, Post-exertional Malaise and ME/CFS 


ME/CFS and Sjögren's Syndrome

Oral complications in Sjögren's Syndrome and chronic Dry Mouth