Hi, The most common causes are one of the following: - Stress and anxiety is the main problem in most of the cases - When you start speaking the thoughts are well channelled and hence there is no problem in the beginning but as the talk progresses the thought process may get distracted or there is difficulty in channelling Hence I would advise you to consult a speech therapist for clinical evaluation. Once the cause is found then you can get a second opinion of a psychiatrist. Use speech therapy. Channelize the thought process. Talk for less time with specific things related to family, friends, work and so on. Your efforts are only going to helps you the most. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. T. Chandrakant, General Surgeon