Dozens of HIV patients identified in NHS email blunder
37 people living with HIV received an invitation from NHS Highland with other recipients visible.
An investigation has been launched after the names of nearly 40 people with HIV were included in an email sent to each patient.
The email was sent out by NHS Highland inviting patients to a support group run by Raigmore Hospital's sexual health service.
A total of 37 patients all got the same invitation - which promised to "respect your anonymity" - with addresses of all the recipients visible.
One man who received the email said he was "stunned" by the health board's error.
The man in his 40s, who asked not to be named, said: "It took me some time to process what I had seen.
"I know it stems from a genuine mistake but anonymity and confidentiality are so important.
"I scrolled the list and saw names clearly in some of those addresses, mine included.
"You feel physically sick, people you know, people you might have been with over the years and it sets off all those dark thoughts you had just after diagnosis."
The invitation read: "We discuss various aspects of HIV treatment and care, support services and current developments in the field of HIV.
"We share our findings of our meetings with the NHS Highland Sexual Health Strategy Group and various HIV-related services such as Waverley Care and the Community Advisor Group.
"Would you like to become involved and have your say? We respect your anonymity so our minutes never identify members present."
NHS Highland apologised in an email to the man and said an investigation would take place.
A spokesman for the health board said: "NHS Highland deeply regrets that this breach of confidentiality has happened and we have contacted patients individually to apologise.
"As per normal procedure, a formal internal review is being conducted to understand how this has happened and to consider any steps to avoid this happening in future."