Some patients on waiting lists are exceeding the maximum dose of the strongest painkillers as they wait for surgery.
Pat Taylor is living in agony while waiting for hip replacement surgery.
Her GP Nicole Anderson said she is also feeling the strain because she feels inadequate to help Taylor deal with her intense pain.
New research says doctors are feeling the strain of caring for the thousands of people waiting for the surgery.
Many GPs are working up to 40 extra hours each month to help ease their patients' pain.
Anderson said she put a priority on Taylor's surgery.
"When I saw her I put her at the top of the highest priority - level five out of five. Unfortunately this reflects the status of the funding of the health system," Anderson said.
Some 80% of nearly 150 GPs surveyed said waiting list patients took up between one to four hours each a month. Most had more than 10 such patients. The biggest burden is battling to keep patients supported and out of pain and reassessing them for surgery.
The Ministry of Health concedes that not all who need joint surgery are getting it and that there are still long waits. But it says progress is being made. It says the number of patients waiting to see a specialist has dropped from 8,000 four years ago to just 2,000 now.