In: used to describe a location within a larger space, such as "in the hospital," "in the patient's room," or "in the operating room."
On: used to describe a surface, such as "on the bed," "on the exam table," or "on the floor."
At: used to describe a specific location, such as "at the pharmacy," "at the clinic," or "at the doctor's office."
To: used to describe movement toward a specific location, such as "to the emergency room," "to the lab," or "to the X-ray department."
From: used to describe movement away from a specific location, such as "from the hospital," "from the clinic," or "from the pharmacy."
With: used to describe a person or thing that is accompanying the patient, such as "with the nurse," "with the doctor," or "with the medication."
By: used to describe the means or method of a treatment, such as "treated by surgery," "treated by medication," or "treated by therapy."
For: used to describe the purpose or reason for a treatment or test, such as "tested for diabetes," "treated for pain," or "screened for cancer."
Of: used to describe a relationship or possession, such as "the diagnosis of cancer," "the symptoms of a cold," or "the medication of the patient."