Hello Hitesh, Welcomeme to HCM!
After reading your question I found that there are two main things- first: your father is having high grade fever (duration is not mentioned), and second :
WBC are raises. Both these points towards possibility of an infection in his body (you have not mentioned any other symptoms like
cold,
cough, or burning urination etc., so I can't pin point the cause).
Because of fever and infection itself, the appetite goes down for some times in many patients and they can't eat. Due to
high fever he must be feeling weak and so, keeps on lying in bed. It is a common presentation, and I don't think that you should worry much.
You should take him to a doctor and get him checked, he might need some more
blood test to find the cause and place of infections. Had I been your treating doctor. I would give him a trial of antibiotic and and
antipyretic.
For time till you take him to a doctor, I can say from my experience that fever should subside with tab.
paracetamol in dose of 500mg, and can be given two to three times a day for two days.
But I would suggest you to visit a doctor in person and get your father checked.
Hope this helps you.
Please feel free to ask anything more for clarification.
Dr. Manisha Gopal