Thanks for your question on Health Care Magic.
I can understand your situation and problem.
By your history and description, possibility of
lung Infection (
pneumonia) is more.
Lung infection is common in asthma patients due to poor lung defense.
And cough, greenish phlegm, weakness,
dizziness etc are common symptoms of pneumonia.
So better to get done chest x ray first.
Chest x ray will also be helpful in screening of
lung cancer.
No blood tests are available for diagnosis of lung cancer.
Non specific tumour markers like CEA, LDH, CA125 etc are raised in lung cancer. But these are non specific and hence diagnosis can not be made on their values.
Screening of lung cancer is done by chest x ray. And fir confirmation, CT thorax and
biopsy are required.
But at present, you need chest x ray to rule out pneumonia.
Hope I have solved your query.
Wish you good health. Thanks.