The whale which lost its way and became stranded in the river Thames in January, was suffering from arthritis, scientists examining its remains said.
The whale mistakenly swam into the Thames in January
The 11-year-old female northern bottlenose was suffering from severe pain in her neck, according to experts at the Natural History Museum.
The 19.2ft (5.85m) whale first surfaced on 20 January after mistakenly swimming into the North Sea and up the Thames.
It died a day later as rescuers tried to take it towards deeper waters.
Experts said the whale may have been trying to head west to the Atlantic Ocean where it could feed on deep sea squid, but took a wrong turn, ending up near Chelsea Bridge in the heart of London.
The curator of the Natural History Museum, Richard Sabin, who has been examining the whale's preserved bones for the past eight months, said the creature may have been in a lot of pain.
The whale was dehydrated and starving for nearly a week
"We found pitting on her atlas vertebra, which joins her spine to her skull.
"It's a degenerative joint disease which in humans is called arthritis.
"Deep-diving whales put their skeletons through lots of punishment," he said.
Experts who carried out an autopsy on the whale said it was dehydrated and had been starving for nearly a week.
Without its normal squid diet, it was unable to rehydrate, they said.
The Museum is storing the whale's bones in its south London warehouse.
The entire skeleton will be kept for scientific research and made available to scientists from around the world.