Do you have a phobia? The definition of 'phobia' varies a little depending on the source you consult. The Macmillan English Dictionary says, 'a very strong feeling of disliking or being afraid of someone or something'. The sixth edition of Health and Wellness (Edlin, Golanty and McCormack Brown) states a phobia is 'a powerful and irrational fear of something.' I think the word irrational is an important difference in these two definitions. I have a fear of snakes which I consider quite rational as a snake bite has the potential to kill. I will admit the degree of my fear of encountering a snake and the places I fear it could happen are somewhat irrational at times.
Wikipedia, quoting from The Anxiety and Phobia Workbook by Edmund Bourne gives a more detailed definition, 'A phobia is a type of anxiety disorder, usually defined as a persistent fear of an object or situation in which the sufferer commits to great lengths in avoiding, typically disproportional to the actual danger posed, often being recognized as irrational. In the event the phobia cannot be avoided entirely, the sufferer will endure the situation or object with marked distress and significant interference in social or occupational activities'.
Common phobias include ophediophobia (fear of snakes), arachnophobia (fear of spiders), mysophobia (fear of germs and dirt) and acrophobia (fear of heights). These fears are based on things one needs to be somewhat cautious about. However, the person with a phobia experiences a much greater level and degree of anxiety than is necessary to keep oneself safe. The person may be aware he/she is far more anxious than necessary. However, he/she will be unable to overcome the intense fear by simply reasoning with him or herself.
A person with a phobia about using an elevator may know it is unlikely the lift will break down. They may be able to say if it did break down it would be inconvenient but a maintenance person would fix the problem and everyone would get out safely. The person might be able to rationalise that those trapped in the lift would not run out of air. However, one with a phobia would still be extremely anxious about using a lift and may avoid doing so.
Phobias can prevent the sufferer from doing activities others do without thinking about. I was amazed at the number of phobias which have been identified and named. Some have several names. I think the longest name in the extensive list was paraskavedekatriaphobia which is fear of Friday the 13th. (Sorry if I didn't get the spelling correct.)
Some phobias would not disrupt daily life and could be lived with. There are other fears such as verbophobia (fear of words), amathophobia (fear of dust) and acousticophobia (fear of noise), to name just a few, which involve things that can't be avoided.
Phobias can be treated. Sometimes people manage to self treat by gradually exposing themselves to the thing they have a phobia about, perhaps with the help of a friend. Therapists have various ways of treating phobias. Sometimes medication initially helps and then therapy is introduced. Hypnotherapy is sometimes used.
It would seem it is possible to develop a phobia about virtually anything. In fact, some people even have phobophobia which is, as you might have guessed, a fear of developing a phobia.