After seeing a doctor about a problem, they'll likely use their general practitioner referral scheme in order to figure out what the best steps for you to take are with regards to optimizing your health.
A general practitioner referral scheme is a process of placing patients according to their needs. If you are in need of help with one particular area of your health, it is best for you to see a professional who specializes in this field as they will be able to give you more directed advice with regards to this particular issue.
Usually the general practitioner referral scheme program will be made up of a combination of professionals, such as medical doctors, dieticians, physiotherapists, chiropractors, physical trainers, psychologists and so on. This enables them to have a broad selection of avenues to choose from when figuring out what treatment will best help bring you back to proper health.
One of the nice things about this set-up is that since the initial doctor you saw will likely keep a record of what is going on with your health status, they will then forward this information directly to whomever you will be seeing for a follow-up, thus the new professional will have your past background. This enables these professionals to work closer together as a team to provide the most comprehensive treatment to you. Be sure however, to still voice any additional concerns when you see the specialist that you did not tell your doctor about. If any changes have occurred with your current health status this is also something that should definitely be brought to attention as it could affect the way in which you are treated.
So don't be afraid to go see your doctor about whatever may be bothering you with your health. Rest assured that if that doctor does not know enough to treat you, they likely will have another specialist they can contact who will.