Anxiety is a (sometimes annoying) emotional and cognitive state. Emotionally, we recognize it as sensations of fear, grief, worry or general apprehension. The cognitive component entails expectation of a diffuse and uncertain danger. The threat or perspective of danger triggers the body’s defenses: the flow of blood to the muscles is increased, which in turn implies rising blood pressure and heart rate. Needless to say, such alert activation involves a higher consumption of body’s energy, and also other parts, such as the immune system, are inhibited in order to increase energetic reserves and focus for fighting the hypothetical danger.