The symptoms of a phobia can range from mild feelings of apprehension and anxiety to a full-blown panic attack. Typically, the closer you are to the thing you’re afraid of, the greater your fear will be. Your fear will also be higher if getting away is difficult.
Physical signs and symptoms of a phobia
Racing or pounding heart
Chest pain or tightness
Trembling or shaking
Emotional signs and symptoms of a phobia
Feeling of overwhelming anxiety or panic
Feeling an intense need to escape
Feeling “unreal” or detached from yourself
Feeling dizzy or lightheaded
A churning stomach
Hot or cold flashes; tingling sensations
Fear of losing control or going crazy
Feeling like you’re going to die or pass out
Knowing that you’re overreacting, but feeling powerless to control your fear
Symptoms of blood-injection- injury phobia
The symptoms of blood-injection- injury phobia are slightly different from other phobias. When confronted with the sight of blood or a needle, you experience not only fear, but also disgust.
Like other phobias, you initially feel anxious as your heart speeds up. However, unlike other phobias, this acceleration is followed by a quick drop in blood pressure, which leads to nausea, dizziness, and fainting. Although a fear of fainting is common in all specific phobias, blood-injection- injury phobia is the only phobia where fainting can actually occur.
Source: http://www.helpguide.org/articles/anxiety/phobias-and- fears.htm