Stress is a normal reaction and can be beneficial in many situations. For instance, a small amount of stress can improve a person's performance or focus. However, this all depends on the amount, duration and impact of the stress that someone is experiencing.

Stress is linked to what is commonly known as the 'fight or flight' mechanism. If a person is in danger, or if an emergency occurs, their body releases certain hormones, including adrenaline and cortisol. These trigger changes in the body to help it either face the danger (fight) or escape from it (flight).

For example, heart rate and blood pressure increase, the body sweats more and blood is diverted to help power the major muscles. If the stressful situation is dealt with and goes away, hormone levels return to normal and the person no longer feels stressed. However, if the stress doesn't resolve, they may continue to feel anxious, jumpy and irritable.

They may also find it difficult to concentrate and become increasingly emotional. Everyone responds to stress differently and some handle it better than others. If stressful situations are constant, there will be detrimental effects over time. Long-term stress can increase an individual's susceptibility to numerous health problems, including heart disease, insomnia, digestive problems, depression and obesity.