Is your glass half-empty or half-full? How you answer this age-old question about positive thinking may reflect your outlook on life, your attitude toward yourself, and whether you're optimistic or pessimistic — and it may even affect your health.

Indeed, some studies show that personality traits such as optimism and pessimism can affect many areas of your health and well-being. The positive thinking that usually comes with optimism is a key part of effective stress management. And effective stress management is associated with many health benefits. If you tend to be pessimistic, don't despair — you can learn positive thinking skills.

Positive thinking doesn't mean that you ignore life's less pleasant situations. Positive thinking just means that you approach unpleasantness in a more positive and productive way. You think the best is going to happen, not the worst.

Positive thinking often starts with self-talk. Self-talk is the endless stream of unspoken thoughts that run through your head. These automatic thoughts can be positive or negative. Some of your self-talk comes from logic and reason. Other self-talk may arise from misconceptions that you create because of lack of information or expectations due to preconceived ideas of what may happen.

If the thoughts that run through your head are mostly negative, your outlook on life is more likely pessimistic. If your thoughts are mostly positive, you're likely an optimist — someone who practices positive thinking.

Researchers continue to explore the effects of positive thinking and optimism on health. Health benefits that positive thinking may provide include:

• Increased life span
• Lower rates of depression
• Lower levels of distress and pain
• Greater resistance to illnesses
• Better psychological and physical well-being
• Better cardiovascular health and reduced risk of death from cardiovascular disease and stroke
• Reduced risk of death from cancer
• Reduced risk of death from respiratory conditions
• Reduced risk of death from infections
• Better coping skills during hardships and times of stress

It's unclear why people who engage in positive thinking experience these health benefits. One theory is that having a positive outlook enables you to cope better with stressful situations, which reduces the harmful health effects of stress on your body.

It's also thought that positive and optimistic people tend to live healthier lifestyles — they get more physical activity, follow a healthier diet, and don't smoke or drink alcohol in excess.

Not sure if your self-talk is positive or negative? Some common forms of negative self-talk include:

• Filtering. You magnify the negative aspects of a situation and filter out all the positive ones. For example, you had a great day at work. You completed your tasks ahead of time and were complimented for doing a speedy and thorough job. That evening, you focus only on your plan to do even more tasks and forget about the compliments you received.
• Personalizing. When something bad occurs, you automatically blame yourself. For example, you hear that an evening out with friends is canceled, and you assume that the change in plans is because no one wanted to be around you.
• Catastrophizing. You automatically anticipate the worst without facts that the worse will happen. The drive-through coffee shop gets your order wrong, and then you think that the rest of your day will be a disaster.
• Blaming. You try to say someone else is responsible for what happened to you instead of yourself. You avoid being responsible for your thoughts and feelings.
• Saying you "should" do something. You think of all the things you think you should do and blame yourself for not doing them.
• Magnifying. You make a big deal out of minor problems.
• Perfectionism. Keeping impossible standards and trying to be more perfect sets yourself up for failure.
• Polarizing. You see things only as either good or bad. There is no middle ground.

You can learn to turn negative thinking into positive thinking. The process is simple, but it does take time and practice — you're creating a new habit, after all. Following are some ways to think and behave in a more positive and optimistic way:

• Identify areas to change. If you want to become more optimistic and engage in more positive thinking, first identify areas of your life that you usually think negatively about, whether it's work, your daily commute, life changes or a relationship. You can start small by focusing on one area to approach in a more positive way. Think of a positive thought to manage your stress instead of a negative one.
• Check yourself. Periodically during the day, stop and evaluate what you're thinking. If you find that your thoughts are mainly negative, try to find a way to put a positive spin on them.
• Be open to humor. Give yourself permission to smile or laugh, especially during difficult times. Seek humor in everyday happenings. When you can laugh at life, you feel less stressed.
• Follow a healthy lifestyle. Aim to exercise for about 30 minutes on most days of the week. You can also break it up into 5- or 10-minute chunks of time during the day. Exercise can positively affect mood and reduce stress. Follow a healthy diet to fuel your mind and body. Get enough sleep. And learn techniques to manage stress.
• Surround yourself with positive people. Make sure those in your life are positive, supportive people you can depend on to give helpful advice and feedback. Negative people may increase your stress level and make you doubt your ability to manage stress in healthy ways.
• Practice positive self-talk. Start by following one simple rule: Don't say anything to yourself that you wouldn't say to anyone else. Be gentle and encouraging with yourself. If a negative thought enters your mind, evaluate it rationally and respond with affirmations of what is good about you. Think about things you're thankful for in your life.

Here are some examples of negative self-talk and how you can apply a positive thinking twist to them:

If you tend to have a negative outlook, don't expect to become an optimist overnight. But with practice, eventually your self-talk will contain less self-criticism and more self-acceptance. You may also become less critical of the world around you.

When your state of mind is generally optimistic, you're better able to handle everyday stress in a more constructive way. That ability may contribute to the widely observed health benefits of positive thinking.