Stress is your body’s survival response to life’s mental or physical demands. When you sense danger, whether it’s real or imagined, the body’s defenses kick into high gear in a rapid, automatic process known as the “fight-or-flight” reaction or the “stress response.”

The fight-or-flight response (also called hyperarousal, or the acute stress response) is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.

Your stress response is the collection of physiological changes that occur when you face a perceived threat, that is, when you face situations where you feel the demands outweigh your resources to successfully cope. These situations are known as stressors.

When we are stressed, our bodies may show physical signs of tension. Sometimes irritation, anger, nervousness or sadness can be a clue you are feeling stressed. You may have difficulty concentrating or feel like you can’t stop worrying about something.

Stress symptoms can affect your body, your thoughts and feelings, and your behavior. Being able to recognize common stress symptoms can give you a jump on managing them. Stress that’s left unchecked can contribute to many health problems, such as high blood pressure, heart disease, diabetes, insomnia, weight gain or loss, digestive issues, depression, headaches, hormonal imbalances, and skin problems.