Summary of discussion：40mm in TB test, what to do ?

First, you need to keep all of your records related to medical exam, make copies of them and keep it safe.
Second, If your TB test is positive and less than 10mm, you need x-ray; If your x-ray is normal, you are good to go. If you TB test is positive and more than 10mm and less than 25mm, you need to do x-ray, if it is normal, you are good to go. But if you come from P.R.CHINA, you might be asked for local health provider to confirm your classification, such as inactive or active but not infectious. If your skin test is more than 25mm and your x-ray is normal, you might have to depend on the doctor's judgement and you might be asked to do more test such as sputum culture. If the culture is negative, your doctor need to write a strong letter to ensure you are not active (your classification)with the evidence (x-ray, sputum culture)against your skin-test.But your doctor have to have a treatment plan and followup plan on that letter if your skin test is larger than 25mm. If your skin test is positive and your x-ray showed that you had active TB before, you need to be classified and a letter from your local doctor to ensure your safety.Hope this covered most of the issue on TB.