CF patients regularly go through certain tests to get a better idea about what’s going on with their bodies, and sometimes have to go through other tests to get a deeper look into a system:
Throat/Sputum Cultures: These are done at every clinic visit, and sometimes happen more often if the need arises (i.e. - after finishing a round of TOBI to see if a pseudomonas infection was eradicated). It tells the CF team what, if anything, is growing in the patient’s lungs.
X-rays: Patients have annual x-rays done of their chest to check for damage and mucus, and can sometimes need them more often if it’s needed. They can also x-ray the bowels to check for blockages.
Blood Work: Like many people without CF, CF patients get annual blood work to check for a host of things, including vitamin levels, blood count, etc.
Pulmonary Function Tests (PFTs): At a certain age, sometimes as early as 4 or as late as 6 depending on the clinic and child, CF patients perform these tests regularly. It measures how well the lungs take in and release air, and can also measure how well they move gasses such as oxygen throughout the blood stream (http://www.nlm.nih.gov/medlineplus/ency/article/003853.htm).
Bronchoscopy: Used to get a better look into the lungs, a scope is inserted into the lungs to see what’s going on inside. A biopsy can also be taken during the procedure if necessary (http://www.nlm.nih.gov/medlineplus/ency/article/003857.htm).
Sometimes other tests are also needed that I have not mentioned in this list.