Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for severe breathing difficulty, fainting, new confusion, blue or gray lips, severe chest pain, or substantial coughing of blood.
Contact the treating clinician sooner than planned if breathlessness, cough, fever, exercise tolerance, or oxygen readings worsen.
New blood in mucus also needs prompt medical advice.
Follow-up depends on the cause and severity.
After pneumonia or another temporary illness, a clinician may reassess symptoms and oxygen levels.
Repeat imaging is not necessary for everyone but may be recommended if symptoms persist, the original finding was unusual, or another condition is a concern.
The article also says
Chronic or unexplained abnormalities may require scheduled pulmonary function tests, oxygen checks, or CT scans.
Timing depends on the diagnosis, treatment, earlier results, and changes in symptoms.
Bring an updated medicine list and details about smoking, work, hobbies, animals, mold, and other inhaled exposures to appointments.
Previous imaging can help determine whether an abnormality is new, stable, or progressing.
Every sign above is quoted from the sofidex article on Alveolar abnormalities. If you are not sure, err upward — it is always reasonable to be checked.