A major study of former soldiers has cast doubt on the existence of Gulf war syndrome.
Illness rates are relatively high among Gulf war veterans
London School of Hygiene and Tropical Medicine researchers quizzed more than 40,000 former soldiers.
The study, published in BMC Public Health, found veterans of the 1991 Gulf War were more likely to report symptoms of ill-health.
But similar symptoms were reported by both those who served in the Gulf, and those who did not.
These included mood swings, memory loss, lack of concentration, night sweats, general fatigue and sexual problems.
The researchers said: "The study confirmed that Gulf war veterans report significantly more symptoms of disease than non-Gulf war veterans in almost all ill-health categories examined, yet there is still no consistent explanation for this discrepancy.
"More than one in every 20 UK servicemen who served in the first Gulf war believes that they have Gulf war syndrome.
"However, in common with other studies of veterans, those who thought that they might have Gulf war syndrome reported exactly the same types of symptom as veterans who had not been deployed to the Gulf.
"They just reported these symptoms at higher frequencies. This finding provides evidence against a unique Gulf war syndrome."
No one cause
The Ministry of Defence, which funded the latest study, has always denied the existence of a so-called Gulf war syndrome.
It argues that there was no single cause of the illnesses reported by veterans from the conflict.
Support groups claim about 6,000 veterans have suffered unexplained ill-health
since the conflict, and more than 600 are said to have died.
An independent inquiry is currently under way, which will hear evidence from
ex-servicemen, medical experts and government representatives to establish the
facts about Gulf war illnesses.
In the latest study, the LSHTM team found that 61% of Gulf war veterans reported at least one new medical symptom since 1990.
This compared with 37% of those who did not serve in the Gulf.
More than one in 20 (5.6%) of those who served in the Gulf believed they had
Gulf war syndrome and a further 40% said they were "unsure".
The Gulf veterans reported conditions such as skeletal and muscular problems
(15.1%), general fatigue (10.8%), memory loss or lack of concentration (7.9%),
and skin allergies (7.6%).
The researchers said there was no real consensus of opinion about the cause of ill-health among Gulf war veterans. But they called for better routine health surveillance of soldiers.
Tony Flint, of the National Gulf War Veterans and Families Benevolent Association, questioned the timing of the release of the study to coincide with the start of the independent inquiry into Gulf war syndrome.
He told BBC News Online: "So many of us are suffering. We were all fit young men prior to going to the Gulf, and now we are either ill or dead.
"It may be true that other veterans report one or two or these symptoms, but most Gulf veterans report at least eight or nine."
Mr Flint said he had posttraumatic stress disorder, asthma, bowel, bladder and stomach problems, damaged discs in his neck and back, nerve damage to his right arm and right leg, memory problems and night sweats.
Vaccines against anthrax and the plague, nerve agents from Iraqi chemical weapons storage facilities, pesticides and exposure to pollution from burning oil wells have all been cited as possible causes of ill-health in Gulf veterans.
The researchers sent a questionnaire to all UK armed forces personnel who had been deployed to the Gulf area some time between August 1990 and June 1991.
The responses from Gulf war veterans were compared with answers from 18,439 male armed-service personnel who had not served in the Gulf.