Hi,
The fear of having serious illness despite knowing that it's irrational can be hypochondriasis. Hypochondriasis is a treatable condition and treatment options include both medicines and psychotherapy (talk therapy).
You should consult a Psychiatrist for proper diagnosis and treatment.
Health Tips
Caution: The above mentioned is one of the possibility and may not be your diagnosis. You should consult a Psychiatrist for proper diagnosis and treatment. Hyderabad does have many competent Psychiatrists.