From this week, the voice-assisted technology is automatically searching the official NHS website when UK users ask for health-related advice.
The government in England said it could reduce demand on the NHS.
Privacy campaigners have raised data protection concerns, but Amazon says all information will be kept confidential.
The partnership was first announced last year, and now talks are underway with other companies, including Microsoft, to set up similar arrangements.
Previously the device provided health information based on a variety of popular responses.
The use of voice search is on the increase. It is seen as particularly beneficial to vulnerable patients, such as older adults and those with visual impairment, who may struggle to access the internet through more traditional means.
Under the partnership, Amazon's algorithm uses information from the NHS website to provide answers to questions such as, "How do I treat a migraine?" and, "What are the symptoms of chickenpox?"
Health Secretary Matt Hancock said it was right for the NHS to "embrace" technology in this way, predicting it would reduce pressure on "our hard-working GPs and pharmacists."
"We want to empower every patient to take better control of their healthcare," he added.