You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A 35 years old male, with pre-morbid anxious traits & heavy smoker, believes that he has been suffering from 'lung carcinoma' for a year, No significant clinical finding is detected on examination and relevant investigation. He continues to stick to his belief despite evidence to the contrary. In the process, he has spent a huge amount of money, time and energy in getting himself unduly investigated. He is most likely suffering from - and explain in detail?
Preoccupation with fear of serious illness (lung cancer), normal clinical examination & investigation and multiple investigations suggest the diagnosis of hypochondriasis.