Provision of a technology capable of realizing estimation of forces of various types of disturbance acting on a robot arm in a surgical environment is desirable. Provided is a medical support arm system including a joint state acquisition unit configured to acquire a state of a joint unit of an arm unit, and an external force estimation unit configured to estimate an external force due to predetermined disturbance on the basis of a condition that the external force due to the predetermined disturbance is limited to one predetermined direction or a plurality of predetermined directions, and a state of the joint unit.