Hi SRobb
I have first hand experience here as I have had Hypnotherapy twice in the past and also now practise Self - Hypnosis.
When I was 18, I couldn't even walk in to a room with more than say, 5 people in or go to the Cinema, theatre etc. The reason for this is turned out to be as simple as wetting myself at school when I was about 5 years old and everybody laughed at me!
I had 5 sessions of Hypnotherapy and cured me enormously. I now run my own company and hold regular board meetings with lots of people. It gave me the confidence. Whereas a phobia is involved say for example scared of spiders, fear of flying etc - these can be resolved easily by simply "Reprogramming/retraining your outlook/thoughts.
To finish, it does work and I would recommend it 100% but just be careful who you choose to go to, find a reputable Hypnotherapist. Hope this helps :o)