A lawyer for Leyla Yunus says the jailed Azerbaijani human rights activist can barely walk and has trouble breathing.
After meeting Yunus at a pretrial detention facility on December 9, lawyer Ramiz Mammadov told RFE/RL that "it took her 30 minutes to walk the 50-meter corridor."
He said Yunus, who he says has Hepatitis C, has received no new prescriptions in the detention center and is now having trouble getting medicine from outside.
Authorities have also refused to give her the results of medical tests.
"She is told the level of diabetes or blood pressure is normal while in fact they are high," Mammadov said. "She tells them, 'You are deceiving me.'"
Yunus, 58, was arrested in July, and her husband, Arif Yunus, was arrested in August.
They are being held separately in pretrial detention on charges of treason and other crimes, which they say are unfounded and politically motivated.
The United States and other Western nations have called for the couple's immediate release.
But increasingly alarming expressions of concern about their health from their lawyers have had no visible effect on the authorities in oil-rich Azerbaijan, whose government has little tolerance for dissent.
Her lawyers say Leyla Yunus is in extremely poor health and has been subjected to beatings and lack of medical care for advanced liver disease.
In a letter to her daughter, Yunus said a group of men in civilian clothes had entered her cell last month and made sexually threatening gestures.
Mammadov told RFE/RL after a previous visit that it appeared disease had "broken her liver. She is in very bad condition; she hardly breathes."
After his visit on December 9, Mammadov said her condition had not improved.
"She has asked for test results but has not been given any," he said.
Mammadov also said she has not been given a hot meal since November 25 and that what food she has is sometimes stolen by other inmates in her increasingly crowded cell when she leaves to meet a lawyer.
He said one of her newer cellmates is a drug addict whose withdrawal symptoms make it impossible for her to rest.
A lawyer for Arif Yunus, also speaking on December 9, told RFE/RL his client is heavily medicated but continues to worry about the fate of his wife.
Khalid Bagirov said Arif Yunus is suffering from insomnia and has been receiving a type of medication since mid-October that is known to cause addiction.
Arif Yunus is "very concerned about Leyla's health," the lawyer said.
Western nations have repeatedly accused President Ilham Aliyev of stifling dissent and restricting basic freedoms since he succeeded his long-ruling father in 2003, but they have cultivated ties with Azerbaijan, whose oil and gas are an alternative to Russian energy supplies for Europe.
The United States said on December 1 that it is "increasingly concerned that the government of Azerbaijan is not living up to its international human rights commitments and obligations."