What is causing her hand pain?

My Mom who is 94 years of age has been suffering from loss of feelings in her fingers and it is painful. She has been dealing with it the past couple of years and as time passes its getting worse. Is this arthritis or from lack of blood circulation in her fingers? Can anything be done to help her? At bedtime she will rub her hands with a pain relieving ointment and wrap them up to help with the pain.