Anxiety and fear are two related but not equivalent concepts.
Fear is a normal body reaction to situations involving an external threat, since an increase in heart rate and level of alertness of the organism and other characteristic signs we have all experienced at one time when we felt threatened or endangered.
Anxiety: What it is
Anxiety is an unpleasant sensation accompanied by signs and symptoms similar to those found when we feel afraid, due to increased secretion of corticosteroids in the adrenal glands and by activation of the sympathetic nervous system with the release of adrenaline and noradrenalin, among others neurotransmitters and hormones.
Anxiety occurs in response to stress; it may be due to various circumstances, of such work, family, etc.
A certain level of anxiety is healthy and adaptive and allows us to cope with adverse life circumstances and solve problems that we encounter.