Colin Douglas was addressing the CIPR's health and medical group last week.
He said NHS communicators are so caught up with reactive work that they are left with insufficient time for proactive comms.
'The level of intensity and scrutiny, the sheer volume of activity and a goldfish bowl mentality make a comms role within the NHS extremely exciting,' he said.
Douglas added: 'Traditionally, the focus has been on reactive media relations but the NHS needs to increase its focus on social marketing, stakeholder and workforce engagement and its online presence.'
Douglas described the key comms challenges facing the NHS as managing extremely high public and political expectations, defending the NHS' reputation, stakeholder engagement on a local and national scale and improving patient empowerment through choice and information.
His comments come as the Department of Health (DH) has published a new framework entitled Ambitions for Health, outlining how it will increasingly rely on social marketing to improve public health. In particular, evidence will be used to motivate people to lead healthier lives.
The framework will outline how social marketing can be used locally, regionally and nationally. Recent social marketing campaigns have included Health Trainers, which provides one-to-one support to help individuals tackle health issues.
PR will increasingly play a role in the DH's strategy, as it focuses on providing new ways of empowering people to make their own choices.
This follows research conducted by the DH that has found that 86 per cent of people think the Government should intervene to prevent illness.