A 41 - year old married female presented with headache for the last 6 months. She had several consultations. All her investigations were found to be within normal limits. She still insists that there is something wrong in her head and seeks another consultation. The most likely diagnosis is:

The patient in question who is persistently preoccupied about her disease (headache) despite of all normal investigations and seeking another consultation is showing features of hypochondriasis. Essential feature of hypochondriasis, is a belief of serious medical illness that persists despite reassurance and appropriate medical evaluation. These patients have a history of poor relationships with physicians because of the feeling that they have been evaluated and treated inappropriately or inadequately. This disorder is disabling in intensity and is persistent, with waxing and waning symptomatology. Ref: Harrison's Principles Of Internal Medicine, 18th Edition, Chapter 391.