Doctors who are experts in one specific area of medicine.
Subspecialists are very knowledgeable and skilled in their specific area of medicine.
Examples:
The heart doctor and the brain doctor are both subspecialists.
Subspecialists help people with very specific health problems.
My mom is a subspecialist. She helps people with problems in their eyes.
The subspecialists work together to help the sick boy.
There are many different kinds of subspecialists, like bone doctors and skin doctors.
The subspecialists are like superheroes for people's health.