you not mention the physical problem like cough,fever,weight loss
,burning micturition,abdominal pain
or passage of red urine.
a single nodule in the lungs have many differential diagnosis like TB,pneumonia,malignancy or metastatic from other tumor(kidney,bladder etc).
according to clinical features some other inv. may be needed like CT scan of chest or bronchoscopy
for proper evaluation consult an internal medicine specialist.