Feeling stressed or anxious
All people start to feel stressed when the demands on them become greater than their resources to deal with them. At lower levels this is can be a positive thing because it stimulates motivation, creativity and new learning, but as stress increases, a point is reached where it can be unhelpful and reduce our ability to function.
Similarly, there are normal levels of anxiety and levels where it starts to be a problem. Some degree of fear or worry can help us respond to life's challenges and alert us to possible dangers in a useful way. But the fear and worry may get out of proportion to the actual level of danger, or become so great that we find it harder to function in everyday situations.
'Anxiety' is a word than can be used for the whole spectrum of fear and worry, but is usually used by clinicians to describe levels that have become problematic in some way. Some people experience an extreme form of anxiety called a 'panic attack'. This can be an intense and alarming phenomenon that is not dangerous in itself but which floods the body with adrenalin and takes 20-30 minutes to subside. See Useful links.
Sometimes people use alcohol or drugs to try and manage their stress and anxiety, or put more and more effort into avoiding feared situations. This may be effective in the short term and bring temporarily relief, but the underlying problem can get worse if it is not faced up to and dealt with. That is when it might be useful to consider talking to a counsellor. Contact counsellingreception@sussex.ac.uk. Or you might like to consider a workshop. See Manage your Stress