<s>[INST] Hi, my 82 year old grandfather has suddenly begun coughing a lot and suffering from fatigue and loss of appetite and gets cold shivers, he has no existing alements and is on blood preassure tablets and zinc for cramps, we are in Texas currently and are due to fly home tomorrow but we are wry worried about him [/INST] Thanks for your question on Chat Doctor. I can understand your grandfathers situation and problem. Lung infection is common in old age due to poor lung defense. He is also having cough, fever with chills, loss of appetite, fatigue etc. And all these are suggestive of lung Infection. So better to get done chest x-ray. He may need antibiotics, antihistamines and anti-inflammatory Chat Doctor.  Early identification of infection and prompt antibiotic treatment is having good prognosis. So get done chest x-ray and start appropriate antibiotic treatment. Hope I have solved your query. Wish you good health. Thanks. </s>