A doctor is only the person with the profession of treating and curing sick.
Doctors help us by taking care in the hospital if we have any injuries or illness.
If there are no doctors and we are injured or ill there will be many chances to lose our lives without doctor in that situation.
There are many doctors like dental doctor, ophthalmologist (eye doctor) etc.. who can help us in different types of illness.
Doctors treat not only physical ailments but also the mental ailments of a patient as a Psychiatrist (medical doctor; who specializes in mental health, including substance use disorders.)
