Hello Welcome to health care magic Dear patient, you are right that you had never been a smoker, drunkard or a drug addict but finding an old patch of fibrosis in your lungs is nothing unusul because it could have simply resulted from the chemical pneumonitis that you would have suffered after inhalation of high denesity benzene perfumes 2 years back. A patch of fibrosis in the lungs is not a big deal because till more than 50% of your lungs are functioning normally, it is not going to affect your breathing much even during . exercises. However the current episode of cough with yellowish sputum and yellowish nasal discharge along with blood tinged sputum following 10 days after flu simply indicates secondary bacterial pneumonitis that can happen as a complication of influenza (flu) and again this in not also a big problem because it can easily get cured with antibiotics and other supportive treatement. However since your age is more than 50 years so it is always better to rule out neoplastic (tumour) lession in the lungs for which you can get HRCT (high resolution CT Scan) of the chest done if that shows there is no neoplastic lession then you should not worry at all about that fibrotic patch wish you speedy recovery thanks Dr Arshad