Passionate and dedicated to the cause, businesses leaders on a mission to help society and the environment are increasingly coming up against an unexpected hurdle - burnout.

Globally social entrepreneurship is on the rise, with more businesses being set up with the aim of making a profit that can be used to address problems like unemployment, homelessness, mental health, knife crime and even loneliness.

But juggling these responsibilities can often take a toll on the business leaders' mental health and wellbeing, according to academics, health professionals, and social entrepreneurs attending two of the sector's major annual events this week.

"Creating a business that does good while simultaneously ensuring that the business itself is sustainable is not an easy task," said Gabriella Cacciotti, assistant professor in entrepreneurship at Britain's University of Warwick.

"The goals of 'doing good' and 'making money' may be incompatible, as making progress towards one of these goals requires actions and decisions that can undermine progress toward the other."

A feeling of burnout weighed so heavily for Rebecca Kaduru that she wanted to throw in the towel on KadAfrica, the passion fruit farming social enterprise she founded with her husband in Uganda in 2014.

"What was so taxing as a social entrepreneur is you've this idea and this dream and you have to go out convince other people to give you money to make it happen," said Kaduru, now managing director of Solidaridad Network, a Dutch ethical trade group.

"There were times I would wake up with really bad anxiety. We had 43 employees in Uganda. What would happen if we couldn't make it work?" she said, adding that the lack of long-term security was also hard to take with a family.

On the rise

It was a serious car crash that brought her role as a social entrepreneur to an abrupt end, forcing her to move back to the United States for surgery. KadAfrica continued without her.

There are no figures to track the burnout rate, but anecdotal evidence suggests it is on the rise, said Dan Gregory, director of international and sustainable development at Social Enterprise UK, the trade body representing the sector.

"People put so much time in and are so passionate about what they do that they do just do not stop," Gregory told the Thomson Reuters Foundation at the Social Enterprise World Forum (SEWF) in Addis Ababa.

Felecia Hatcher, co-founder of Code Fever and Blacktech Week, organizations supporting black social entrepreneurs, said she had suffered several episodes of burnout in recent years.

Juggling her two Miami-based ventures, which she runs with her husband, with looking after young children, Hatcher said social entrepreneurs often struggle to see signs of burnout.

"We can fail to communicate what we're feeling and how tired we are, and how hopeless it feels sometimes to be following your dream, without any kind of instruction book," said Hatcher at the SOCAP (Social Capital Markets) conference in San Francisco.

Financial pressures - whether it is raising capital to run the business or earning enough to make a living - can also take a toll, said Sabrina Chakori, 27, an Australia-based social entrepreneur who runs a "tool library" where people can borrow - rather than buy - DIY equipment, camping and sports gear.

"For a long time impact investors never trusted social enterprises but in reality social entrepreneurs would give their life to the cause and this can lead to burnout. I feel I am overworked," said Chakori.