The former president underwent a liver transplant in the 1990s. And in early December 2007, he was admitted to a hospital in Nairobi for treatment of what his spokesman described as bronchitis.
On January 4, 2008, he collapsed in Baidoa and was taken to Ethiopia for treatment.
Two days later he was rushed to London for tests. He returned to Mogadishu on February 16, 2008, only for rebels to fire mortars at the presidential compound, reportedly wounding five people.
Ahmed has, however, had a long history of living on the edge. As an army officer he has been restless throughout his life and perhaps played a role in the current destabilisation of Somalia.
Ahmed had led one of the clan-based rebel groups called the Somali Salvation Democratic Front in the north, which consisted of several former army officers opposed to Siad Barreâs regime.
Barre was finally overthrown on January 26, 1991, when factions led by warlord Mohamed Farrah Aidid and his rebel group, the United Somali Congress, invaded Mogadishu.
When Barre, then the commander of the army staged a coup in Somalia on October 21, 1969, Ahmed was then serving in the Somali army as a soldier.
The coup had followed the assassination of Somaliaâs then President Abdirashid Ali Shermake by one of his bodyguards on October 15, 1969.
Ahmed had joined the army during the 1950s, and was promoted to the post of commander in 1960.
As a soldier, he participated in the Somali-Ethiopian war of 1964 and was decorated for bravery. He had also served as Somaliaâs military attachÃ to Moscow between 1965 and 1968.
Ahmed was, however, imprisoned soon after the coup by the military regime for refusing to support Barreâs seizure of power.
He was released from prison in 1975 and appointed as the director of a government agency and later commanded the Somali National Armyâs southern front in the Ogaden War against neighbouring Ethiopia.