Jack has been caring for his elderly father for some time, and is beginning to feel the pressure of being a caretaker. For no identifiable reason, he has begun doing things that cause his father to become sick, so that his father can spend time in the hospital. He also finds that he enjoys the attention he gets when his father is sick. Jack may be diagnosed with:

Factitious disorder imposed on another is a psychological disorder in which a person who is taking care of another person acts and creates a situation that leads people to believe that the person in care is sick when in reality they are not.
A person who is taking care of another person can either deliberately cause the person in care to become sick or can either lie about it.
People use this to gain sympathy for all the hard work they are putting in to take care of the person and often exaggerate the illness.
In the given situation, Jack who is taking care of his father is also resorting to deceptive means to make his father sick and is enjoying the attention he gets due to his sickness and thus, he is suffering from factitious disorder imposed on another.