Doctors in southwest China have successfully removed a bullet from a woman's head 42 years after she was shot, putting an end to decades of increasingly unbearable pain, state media said Friday.

Staff at a hospital in Chongqing municipality extracted the inch-long (2.5-centimetre) bullet from the right temple of He Wenying, 65, on Thursday, the Chongqing News reported on its website.

She was hit by the ricocheting bullet during a gun battle between warring factions at the start of the Cultural Revolution, which lasted from 1966 to 1976.

Doctors initially told her that her wound was only superficial, but constant headaches and difficulty eating led to an x-ray in 1978 that revealed the bullet lodged near her right jaw and ear, it added.

Still, the accountant and mother-of-three refused an operation because of poor medical facilities in Chongqing and instead endured increasingly severe headaches.

Earlier this year, pain from the wound started spreading over her entire body, prompting Thursday's operation, it said.