Hi thanks for contacting HCM.... Usually cough and cold doesn t affect liver function test ... If needed LFT evaluated through USG and liver enzymes estimation to rule out gall stone or fatty liver like condition .. If needed than hbsag estimation like investigation done to rule out viral carrier .. Here as cough more than three month as you have mentioned , investigated with digital chest x ray and sputum examination for cytology .... This might be bronchitis like condition ... You might given antibiotic ... You might need decongestent like benadryl ... Steam inhalation done daily .... Drink more water. Avoid excess spicy and fried food that can aggravate cough ... Take care Dr.Parth Advise : pulmonologist consultation for examination ..