London, Dec 14 : An Australian doctor has diagnosed the mysterious illness that 19th-century scientist Charles Darwin suffered from, as being "cyclical vomiting syndrome".

John Hayman, associate professor at Monash University in Melbourne, suggested that the author of ''On the Origin of Species'' had inherited the unusual disorder, reports the Guardian.

Darwin''s condition had for a long time been a historical and medical mystery, with nausea, vomiting, headaches, stomach and skin problems being the symptoms of the illness.

He had even recorded his anxieties about his medical state in his diary before he set out on his pioneering voyage to South America on the survey ship HMS Beagle in 1831.

"I was ... troubled with palpitations and pain about the heart, and like many a young ignorant man, especially one with a smattering of medical knowledge, was convinced that I had heart-disease," he wrote.

"I did not consult any doctor, as I fully expected to hear the verdict that I was not fit for the voyage," he stated.

In the past, there has been speculation that Darwin may have been a hypochondriac, experienced panic disorders, been emotionally scarred by "repressed anger towards his father", nervous about relations with his wife or have felt guilt over conflicts with his earlier religious belief.

Possible physical diagnoses have included middle ear infection, arsenic poisoning and tropical parasitic infections, such as Chagas disease.

Hayman, of the anatomy and developmental biology department at Monash University, argues in the Christmas edition of the British Medical Journal that it is time to "refute the many fanciful proffered diagnoses, both physical and psychological or psychoanalytical".

He said cyclical vomiting syndrome mainly affects children but can appear for the first time in adulthood.

"The syndrome is related to migraine but is linked to genetic abnormalities," he said.

"Classic symptoms of cyclical vomiting syndrome include severe sickness, headaches, anxiety and intense abdominal pain. Many patients also suffer from eczema and recurrent skin infections," he stated.

Hayman said, Darwin''s mother and members of her family suffered from many of these conditions, and his mother died from severe abdominal pains when he was eight.

"Darwin was not aware of mitochondria or of genes and genetic mutations but he was very aware of random variations within species," he said.

This was the keystone for his theory of the survival of the fittest, the driving mechanism of evolution.

"His personal inherited genetic variation made him substantially ''less fit'', but his survival prospects were greatly increased by his driving intellect; loyal colleagues; devoted wife, family, and household servants; and personal wealth," Hayman added. (ANI)