Gulf War illness (GWI), the chronic, debilitating condition linked to military service in the 1990-1991 Gulf War, will receive a dedicated diagnostic code in the October 2025 release of the International Classification of Diseases (ICD-10-CM). The new code is being hailed as a major step forward by veterans with GWI, and by health care providers and scientists with expertise in the condition.
“This is more than just a code,” said Beatrice Golomb, M.D., Ph.D., professor of medicine at University of California San Diego School of Medicine, who led the successful ICD code submission. Golomb, who has conducted numerous studies on GWI over the past three decades and has contributed materially to understanding of exposure relations, illness features, objective markers, underlying mechanisms and treatments targeting these mechanisms. “This is long-overdue validation for the suffering of the quarter-million afflicted veterans — and a formal acknowledgment that their illness is real, physical and service-related.”
GWI affects an estimated one-fourth to one-third of the nearly 700,000 U.S. troops that were deployed to the Gulf War. It is defined by a profile of symptoms, consistently identified across Gulf War veteran populations, that include persistent fatigue, cognitive difficulties, chronic pain, respiratory issues, skin problems and gastrointestinal distress. Studies consistently indicate that GWI is strongly linked to chemical exposures during the Gulf War and is associated with multiple objective abnormalities — including structural brain changes, mitochondrial dysfunction, inflammation and immune system changes.
ICD codes — the standard system used to classify diseases and health conditions — are critical for everything from diagnosis and research to insurance reimbursement. New codes are accepted after an established, rigorous process involving evidence review, panel presentations and public comment, culminating in formal adoption by federal health authorities.
“Having an ICD code is important because it validates Gulf War illness as a medical disorder, which we hope will help Gulf War veterans get the help they need,” said Kimberly Sullivan, Ph.D., who leads the Boston Biorepository, Recruitment and Integrative Network for GWI at Boston University School of Public Health. “Every day there are veterans walking into their doctor’s office, and those care providers just don’t know about this illness. Having an ICD code helps to educate these providers about this difficult disorder and to diagnose it properly.”
“Without a diagnostic code, we've had to diagnose related conditions like fibromyalgia or chronic fatigue syndrome to prove our patients have a chronic illness, only implying it's related to Gulf War illness,” said Nancy Klimas, M.D., who currently leads the Gulf War illness Clinical Trials and Interventions Consortia at Nova Southeastern University. “This code will help speed research by allowing us to identify patients through medical record searches rather than relying on social media and word-of-mouth.”
For many veterans, official recognition of Gulf War illness will make a tangible difference in how they access and receive care. Anthony Hardie, Gulf War veteran and national chair and director of the advocacy group Veterans for Common Sense, stated: “With use of this diagnostic code over time, there is real potential for better monitoring of health problems, tracking effective treatments and identifying related conditions. All that will help our veterans who are suffering from this disease.”
“The single most important thing for me about this new code is validation of an illness that has impacted me for 34 years,” said Ronald Brown, Gulf War veteran and toxic wounds consultant for Vietnam Veterans of America.
In addition to improving clinical care, the diagnostic code will greatly facilitate future research and public health surveillance. Researchers will now be able to more accurately identify and study GWI populations, track treatment responses and understand how GWI interacts with other conditions — such as amyotrophic lateral sclerosis (ALS) and other neurologic conditions, brain cancer and other cancers, lung and heart diseases, infections, gastroesophageal reflux disease and sleep apnea.
“It’s a big step forward for medicine, research and the health of our military community,” said Denise Nichols, a nurse, Gulf War veteran and veterans advocate.
Veterans and researchers alike credit the achievement to the persistent efforts of scientists, clinicians and advocates working collaboratively on this problem since the 1990s, when veterans first reported difficult symptoms after returning from service in the Gulf War. “We owe a debt of gratitude to the small army of doctors, researchers and veterans who made this happen,” said Boe Marshall, another veteran living with GWI. “They have worked side-by-side — in labs, in hearings and on government panels — to shine a light on Gulf War illness. This diagnostic code is a tribute to that persistence.”
