Senior aides on Sunday said tests carried out have established that Arafat did not have blood cancer or any other critical illness.
"The latest tests have found that President Arafat does not suffer from any life-threatening illness and what he has is curable," senior aide Nabil Abu Rudaina said.
Arafat underwent a battery of medical tests on Saturday at a military hospital in France.
He flew to the hospital outside Paris on Friday after leaving his battered compound in the West Bank city of Ram Allah.
Another Arafat-aide said the doctors were also looking into the possibility of viral infection or poisoning.
The final test results will be ready by Wednesday, the aide said, adding that visitors to the Palestinian president would be limited to just a few people until then.
Muhammad Rashid, another aide, said Arafat was sleeping much better, eating moderately and keeping his food down.
"Tests have found that he does not have leukemia, the doctors are looking at other possibilities," he said.