Obviously, passion is a must when you are an entrepreneur. The long days, hard work and stress can make even the most diligent person think about giving up. It's the passion that allows us to keep going in the face of sometimes overwhelming odds.

However, you must have the right kind of passion, according to researchers from North Carolina State University, the University of Richmond and University of Amsterdam.

They conducted a study in 2016 with 326 members of Business Networking International from a region in the southwest of the United States. The researchers wanted to ascertain whether job passion, job fit and destiny belief made entrepreneurs more or less likely to experience burnout than employees.

Job passion was defined as having a strong inclination toward work that one liked and found important. Job fit was defined as how well the person thought their current job matched their ideal job. Destiny belief was defined as a belief that they were destined to be a successful entrepreneur.

Researchers further broke passion down into two categories: harmonious passion, -- when someone is motivated by the job because it brings them satisfaction and is an important part of who they are -- and obsessive passion -- when the job is important to someone because of the status, money, or other rewards that it brings.

In a write up about the study in the Harvard Business Review in April 2018, the researchers said 25 percent of entrepreneurs who took the survey felt moderately burned out, while three percent felt strongly burned out.

Using a five-point grading scale, the researchers also found that the majority of entrepreneurs reported high levels of job fit (4.26) and harmonious passion (3.90) and average levels of obsessive passion (2.58) and destiny belief (2.79).

When passion goes awry, burnout may be close behind.

Entrepreneurs who reported high scores when it came to obsessive passion were also more likely to say they experienced burnout than entrepreneurs who scored highly on harmonious passion.

The obsessively passionate entrepreneurs said their work was more emotionally draining and required a lot of effort and caused them frustration, anxiety and stress. They viewed their careers as important because of pressures like social acceptance, status, money, and other outcomes associated with being an entrepreneur.

Conversely, entrepreneurs who reported high harmonious passion said they were absorbed during their work week, but took breaks from running their companies and balanced their work with other activities in their lives without feeling any guilt about not being at their job during those times. They also felt like their entrepreneurial careers, while important to them, didn't completely define their lives.

If it weren't for passion, I would not have been able to get my businesses off the ground. The long hours, the uncertainty and the sometimes maddening people I had to deal with all required a healthy dose of passion. Fortunately, I never let it become unhealthy.

Here are three things you can do to avoid becoming obsessively passionate about your business and burning yourself out.

1. Define success for yourself.

I think part of the reason entrepreneurs become obsessively passionate is because they aren't sure when they've become successful. If you've never defined success for yourself, you'll never know if you've reached it.

When I started my main business, I had a certain revenue number in mind per month that I knew would make it cash positive and allow me to focus on the business rather than paying the rent on my apartment and surviving. After I reached that point, I felt like the business had succeeded and everything after that was a bonus.

2. Spread your passion out.

Aside from my business, I have other passions, which I believe help take my mind off it. Charitable work, my gaggle of dogs, helping my sons out with their numerous projects, these are all things I do in addition to running a business. It's important to have multiple outlets for passion because it can become toxic if you concentrate on one thing too much.  

3. Keep the big picture in mind.

Not to get too existential here, but in the words of economist John Maynard Keynes: "In the long run, we are all dead." Always remember that what you think is worth being passionate about might not be so important in the grand scheme of things. When you're 80 years old, are you going to look back at life and fervently wish that you had spent more time building your business? Probably not. I try to keep what's important in perspective. When I'm up there in age, I want to look back and know that my passion was put toward things that really matter to me like my family.

Passion is undoubtedly a good thing when starting a business, but it is a fire that burns hot. If you're not careful, it could lead to burnout.