The kids are screaming, your in-laws are coming to stay, the bills are due and you've got deadlines at work. It's undeniable: Life is full of stress. Understanding the types and sources of stress — short-term and long-term, internal and external — is an important part of stress management.

Stress is your body's reaction to the demands of the world. Stressors are the events or conditions in your surroundings that trigger stress. Your body responds to stressors differently depending primarily on whether the stressor is new or short-term (acute stress) or whether it's been around for a while (chronic stress).

Acute stress

Also known as the fight-or-flight response, acute stress is your body's immediate reaction to a perceived threat, challenge or scare. The acute-stress response is immediate and intense, and in certain circumstances it can be thrilling, such as having an interview for a new job.

A single episode of acute stress generally doesn't cause problems for healthy people. However, severe acute stress can lead to mental health problems, such as post-traumatic stress disorder. It can also cause physical difficulties such as tension headaches, stomach problems or serious health issues, such as a heart attack.

Chronic stress

Mild acute stress can be beneficial because it can spur you into action, motivate or energize you. The problem occurs when stressors pile up and stick around. Then the stress becomes chronic, which can lead to health problems, such as headaches and insomnia. The chronic-stress response is subtler than the acute-stress response, but the effects may be longer-lasting and more problematic.

Know your stressors

Start by identifying your sources of stress. Then you can develop strategies to manage them. Make a list of the situations, concerns or challenges that trigger your stress response. You'll probably notice that some of your stressors are events that happen to you, while others seem to originate from within.

External stressors

These are events and situations that happen to you, such as:

Major life changes. Positive changes (a new marriage, a planned pregnancy, a promotion or a new house) and negative changes (divorce or the death of a loved one) can cause stress.

Unpredictable events. Out of the blue, uninvited house guests arrive. Or you learn that your rent has gone up or that your pay has been cut.

Workplace. An impossible workload, endless e-mails, urgent deadlines and a demanding boss.

Social. Meeting new people can be surprisingly stressful. Relationships with family often spawn stress, too. (Think back to your last fight with your partner.)

Dealing with external stressors: Boost your resiliency by eating a healthy diet, being physically active and getting enough sleep. Asking for help from others, learning to be assertive and practicing problem-solving and time management may also reduce the impact of your external stressors. Carefully consider how you spend your time and energy and focus on the things that are important to you by paring down the number of activities you're involved in, and saying no to new commitments.

Internal stressors

Not all stress stems from things that happen to you, however. Much of stress is self-induced. Those feelings and thoughts that pop into your head and cause you unease are known as internal stressors. They include:

Fear. Fear of failure, fear of public speaking, fear of flying.

Uncertainty and lack of control. Few people enjoy feeling out of control or uncertain about what is going to happen. (Think about how you might react when waiting for the results of a medical test.)

Beliefs. These might be attitudes, opinions or expectations. You may not think often about your beliefs, but they shape your experience — and they can set you up for stress. Consider the expectations you put on yourself to create a perfect holiday celebration or advance up the career ladder.

How to help: We have the ability to control our thoughts. Although our fears, attitudes and expectations have been our companions for a long time, we can change them. Strategies to manage internal stressors include reframing your thoughts and choosing a positive mind-set, challenging negative thoughts, using relaxation techniques and talking with a trusted friend or counselor.

By beginning to identify and understand the sources of your stress, you're taking the first steps in learning to better manage it.

Yes, manage it, not eliminate it. Stress is a fact of life, but with some effort and help, one we can learn to handle.