text: Most scientists agree that a bit of stress is good for you, stimulating your body to produce an important hormone called cortisol. But too much is bad for your health and now an expert has revealed exactly why in a video. In it she reveals why prolonged periods of stress - due to money and work, for example - can inhibit the immune system and even lead to weaker bones. Scroll down for video . A University of Nebraska researcher has revealed why stress is bad for you in a video (still image shown). Limited periods of stress are good, as they release the hormone cortisol. This is useful in helping you recover from very tense situations. But too much will lower your immune system and make your bones fragile. The science of stress was explained in a video by Dr Raychelle Burks from the University of Nebraska-Lincoln for the American Chemical Society. Cortisol is known as the 'stress hormone'. Normally, it's present in the body at higher levels in the morning, and at its lowest at night. Although stress isn't the only reason that cortisol is secreted into the bloodstream, it has been termed the 'stress hormone' as it is released when the body is in 'fight or flight' mode. As she explains, when you encounter a stressful situation ‘your body will start releasing [the hormones] adrenaline and norepinephrine within seconds to prepare you to fight - or more likely, take flight.’ After a minute or two your body is flooded with cortisol, which is vital in keeping you healthy in tense situations. Cortisol puts more glucose into your bloodstream so that when the adrenaline is gone you don’t crash. ‘It also kicks your liver into gear, pumping out the extra glucose that’s now sloshing around inside of you,’ Dr Burks explained. But if you stay stressed for too long, it can have negative effects. After a minute or two of being stressed (stock image shown), your body is flooded with cortisol, which is vital in keeping you healthy in tense situations. But too much will lower your immune system, and could also make your bones more fragile, according to Dr Raychelle Burks from the University of Nebraska-Lincoln . ‘Cortisol inhibits some of your immune responses, meaning you’re more likely to get sick and it takes longer for wounds to heal,’ Dr Burks continued. ‘Cortisol also slows bone growth, meaning sustained levels can lead to weaker, more fragile bones. ‘And because cortisol acts on a part of your brain that controls appetite, it also increases your desire for fatty and sugary foods.’ One positive side effect of too much cortisol, though, is that cortisol is good at reducing swelling or itching in its medical form - known as hydrocortisone. However, remaining stressed for too long is still not advisable - and Dr Burks recommends eating healthy food, exercising and getting plenty of sleep to beat stress.
target: University of Nebraska researcher has revealed why stress is bad for you .
  Limited periods of stress are good, as they release cortisol .
  This is useful in helping you recover from very tense situations .
  But too much will lower your immune system and make your bones fragile .