One of the following usually differentiates hysterical symptoms from hypochondriacal symptoms -
The preoccupation in hypochondriasis is based on a misinterpretation of physical symptom in the presence of normal body function. For example, an occasional change in heart rate will lead a person with hypochondriasis to fear of severe heart disease.
On the other hand, hysterical symptoms are not due to misinterpretation of physiological response.
Symptoms do not normally reflect understandable physiological or pathological mechanism
Physical symptoms are prominent which are not explained by organic factors
Personality traits are significant
Symptoms run a chronic course