No matter how passionate you are about your business, the stress, long hours, and a myriad of worries can leave you feeling unhappy at work. According to a June 2012 report by the Conference Board, an independent business membership and research association, only 47% of Americans are satisfied with their jobs.

"We spend way too much time at work to not behappy, " says Beth Thomas, author of Powered by Happy: How to Get and Stay Happy at Work (Sourcebooks, 2010). Being unhappy at work can not only affect your mood, but your productivity and your company's bottom line.

Bring joy into your job and improve your company's success with these tips:

1. Stay rooted in the present. "Many of our negative thoughts come from worrying about situations that may never happen, " says Thomas. While entrepreneurs often have to make contingency plans, constantly thinking about the worst case scenario can place undue stress on your body and mind and drain it of resources that are better used in more productive ways.

"The best way to deal with negative thoughts is to separate fiction from fact, " says Thomas. So, the next time you find yourself facing a negative thought, analyze the situation and ask whether you're reacting to a real or imagined situation.

2. Engage in positive thinking. Shifting negative thoughts to positive ones can help to improve your mood and mindset. "Every time a negative thought comes into your head, stop and think about a positive one, " says Thomas. Do this for a few weeks and you'll quickly notice that you're creating a new habit that will enhance your happiness not only at work, but in your daily life.

3. Help others. Whether getting involved in philanthropic activities or helping your staff improve in their jobs, Thomas says charity is the secret to lasting happiness. "Happiness at work isn't about what you alone achieve. It's not about helping yourself look better, but about making everyone on your team perform better, " says Thomas.

Setting up an employee mentoring program where senior staff members assist junior staff, or getting your staff involved in a philanthropic activity such as a local food drive or a charity cycling event can improve the happiness of everyone in the office.

4.Take a break. While entrepreneurs are often motivated by positive stress, the kind that pushes us to do more, it's important to recognize when your mind and body need a break. "Even if you like your job, stress can weigh you down and make you unhappy, " says Thomas. Schedule a few days off or find an outlet after work or on the weekend to have fun, rest your mind and rejuvenate yourself.