Answer:
Illness anxiety.
Explanation:
Illness anxiety may be defined as the medical disorder is an anxiety in which the individual feels he may become seriously ill. This is also known as hypochondriasis.
Bertram is over concerned about his health. He does not suffer from any disease and by reading an article he assume that he might be suffering from tumor. Bertram is over thinking and has health anxiety. His present condition clearly indicates the condition of illness anxiety.
Thus, the answer is illness anxiety.