The report has been hailed as a breakthrough by Douglas Henderson, the Armed Forces Minister. He said the research would prompt the Government to act, if it was supported by Ministry of Defence studies.
The research, carried out by the Centre for Disease Control and Prevention at Atlanta University, Georgia, is the first attempt to organise and define clinically a range of symptoms reported by Gulf War veterans in the US Air Force.
"This is the first self-standing study to show that Gulf War Syndrome is a definable disease," Mr Henderson said.
"It is also an important step in trying to find the cause. If it can be shown that British veterans are suffering because they fought in the Gulf defending our freedoms and values, then we have an obligation to act."
Many of the 50,000 British veterans of the 1991 war have complained of illness, blaming excessive use of pills or exposure to chemicals. Some veterans have accused the MoD of a cover-up.
The medical establishment has for years dismissed the veterans' complaints as psychosomatic, in the absence of evidence to the contrary.
The Atlanta study found three categories of symptoms - fatigue, "low mood cognition", including depression, and stiffness in joints.