A medical bulletin said today the cancer that afflicts him has spread through his body.
"A scan has shown a worsening of the disease which has spread more than before,'' said the bulletin from the Tripoli Medical Centre where Megrahi is being treated for terminal cancer.
The bulletin said Megrahi, 57, arrived at the hospital on Saturday coughing and vomiting.
He was also suffering from "secondary effects of the sessions of chemotherapy'' that he has been undergoing, including a weight gain, high blood pressure and sugar in the blood along with muscular fatigue.
"His condition was examined Saturday by a team of European experts who agreed on the continuation of chemotherapy sessions while also administering other medicaments to treat the disease,'' the hospital said in its first bulletin released since Megrahi's return in August.
Under the terms of his release from a Scottish jail on compassionate grounds, Megrahi cannot leave Tripoli or change his address and must keep in regular contact with East Renfrewshire Council.
"We have now spoken to Mr Megrahi, who is in his house. There is no cause for alarm, he is in his house,'' said a spokesman for East Renfrewshire Council in western Scotland.
Megrahi is the only person convicted over the December 1988 bombing of a New York-bound Pan Am Boeing 747 over the Scottish town of Lockerbie, which killed 270 people.
He was freed on August 20 after doctors said he had only three months to live, and returned to a hero's welcome in Libya, angering relatives of those killed.
His release also caused tensions between Britain, the devolved Scottish government and the United States and sparked questions about London's growing trade relationship with Tripoli.