Whether you're guffawing at a sitcom on TV or quietly giggling at a newspaper cartoon, laughing does you good. Laughter is a great form of stress relief, and that's no joke.

A good sense of humor can't cure all ailments, but data is mounting about the positive things laughter can do.

A good laugh has great short-term effects. When you start to laugh, it doesn't just lighten your load mentally, it actually induces physical changes in your body. Laughter can:

• Stimulate many organs. Laughter enhances your intake of oxygen-rich air, stimulates your heart, lungs and muscles, and increases the endorphins that are released by your brain.
• Activate and relieve your stress response. A rollicking laugh fires up and then cools down your stress response, and it can increase and then decrease your heart rate and blood pressure. The result? A good, relaxed feeling.
• Soothe tension. Laughter can also stimulate circulation and aid muscle relaxation, both of which can help reduce some of the physical symptoms of stress.

Laughter isn't just a quick pick-me-up, though. It's also good for you over the long term. Laughter may:

• Improve your immune system. Negative thoughts manifest into chemical reactions that can affect your body by bringing more stress into your system and decreasing your immunity. By contrast, positive thoughts can actually release neuropeptides that help fight stress and potentially more-serious illnesses.
• Relieve pain. Laughter may ease pain by causing the body to produce its own natural painkillers.
• Increase personal satisfaction. Laughter can also make it easier to cope with difficult situations. It also helps you connect with other people.
• Improve your mood. Many people experience depression, sometimes due to chronic illnesses. Laughter can help lessen your stress, depression and anxiety and may make you feel happier. It can also improve your self-esteem.

Are you afraid that you have an underdeveloped — or nonexistent — sense of humor? No problem. Humor can be learned. In fact, developing or refining your sense of humor may be easier than you think.

• Put humor on your horizon. Find a few simple items, such as photos, greeting cards or comic strips, that make you chuckle. Then hang them up at home or in your office, or collect them in a file or notebook. Keep funny movies, TV shows, books, magazines or comedy videos on hand for when you need an added humor boost. Look online at joke websites or silly videos. Listen to humorous podcasts. Go to a comedy club.

• Laugh and the world laughs with you. Find a way to laugh about your own situations and watch your stress begin to fade away. Even if it feels forced at first, practice laughing. It does your body good.

  Consider trying laughter yoga. In laughter yoga, people practice laughter as a group. Laughter is forced at first, but it can soon turn into spontaneous laughter.

• Share a laugh. Make it a habit to spend time with friends who make you laugh. And then return the favor by sharing funny stories or jokes with those around you.
• Knock, knock. Browse through your local bookstore or library's selection of joke books and add a few jokes to your list that you can share with friends.
• Know what isn't funny. Don't laugh at the expense of others. Some forms of humor aren't appropriate. Use your best judgment to discern a good joke from a bad or hurtful one.

Go ahead and give it a try. Turn the corners of your mouth up into a smile and then give a laugh, even if it feels a little forced. Once you've had your chuckle, take stock of how you're feeling. Are your muscles a little less tense? Do you feel more relaxed or buoyant? That's the natural wonder of laughing at work.