The High Court has rejected an appeal bid by a Cairns doctor involved in a multi-million-dollar lawsuit with a former patient.

In 2008, Dr Kaylene Ferguson treated Nancy Mules for a range of symptoms, including neck soreness, headaches and flushing.

She diagnosed a musculoskeletal condition but Ms Mules was actually suffering cryptococcal meningitis, which eventually left her blind and deaf.

In 2013, the Supreme Court in Cairns ruled that Dr Ferguson had not breached her duty of care but that was overturned by Queensland's Court of Appeal, which awarded Ms Mules $6.7 million, finding Dr Ferguson failed to properly investigate her symptoms.

Last week, in the High Court, Dr Ferguson sought special leave to appeal against that decision.

Her lawyers argued that even if Dr Ferguson had done what was required, the disease still would not have been diagnosed.

However, the court ruled the legal principles the decision was based on were sound and ordered Dr Ferguson to pay Ms Mules' court costs.