Life can be full of frustrations. How can you change your mood when you have started your day off on the wrong foot? How do you stop annoyances from dragging you down and killing your productivity?

The good news is you can turn a bad day into a good one. "Happiness is a choice," says Shawn Achor, author of The Happiness Advantage. Even when something objectively negative happens, it's important to focus on the positive things that are also happening.

“Studies show that when you’re positive, you’re 31 per cent more productive, you’re 40 per cent more likely to receive a promotion, you have 23 per cent fewer health-related effects from stress and your creativity rates triple,” he explains.

Discontent is also contagious, adds Annie McKee, the founder of the Teleos Leadership Institute and co-author of Primal Leadership. "Your negative emotions spread like wildfire," she explains. "It's worth changing your mood, not just to make your day more pleasant and productive but to spare those around you."

So what can you do when you are in a downward spiral? Here are some ideas:

Pinpoint the problem

The earlier you catch your bad mood, the easier it will be to do something about it. “We have to have early warning signals that tell us that our resilience is dwindling,” says McKee. She recommends pausing regularly to check your emotional state.

Take a moment to be grateful

As soon as you start to feel negative, short circuit your mood by asking yourself: What are three good things that are going on right now? Consider saying them out loud or writing them down. This will help you get some perspective on the bad day.

Sure, you may have had a fender bender or missed an appointment, but there are other, perhaps more important, things in your life that are going well.

Take action

Send that email that you have been meaning to get to or make a phone call you’ve been dreading. Even choosing a healthier snack, a piece of fruit over a candy bar, can create a positive “mental avalanche” for the rest of the day. “Your brain records a victory,” Achor explains.

Change your routine

If you are feeling miserable, don’t hunker down at your desk for the rest of the day. A change of scenery often helps signal to your brain that the current mood doesn’t need to be sustained. “Drive around, take a walk, or just go to a different floor. The key is to put yourself in a different physical location,” McKee advises. And once you’re there, take a few deep breaths.

Reset realistic expectations

If your mood is deteriorating because it’s after lunch and you feel behind, don’t despair. “You can rewrite the narrative on the day,” he says. Highlight what progress you have made. And then make a list of “short, attainable goals” for the rest of the day.

Learn from your bad days to prevent future ones

When you do have a bad day, it’s important to reflect on them before you put them behind you. By taking note of what went wrong – and then right – you can “learn what your triggers are so you stay away from those particular stimuli or at least know how you’re likely to react if you’re triggered”, McKee says.

If you've tried the above strategies, make a note of what works for you and what doesn't, and "be more precise in the future in how you turn things around". – (Copyright Harvard Business Review 2015 ) Amy Gallo is a contributing editor at Harvard Business Review