Is it serious that the lung markings are slightly increased?

The severity of increased lung markings depends on the specific circumstances. Sometimes increased lung markings may only be acute bronchitis, which is normally mild, and even healthy adults may report increased lung markings on chest radiographs. However, increased lung markings may also be seen in cardiac insufficiency, possibly pneumonia, which is normally severe. Even increased markings on both lungs may be seen in bronchiectasis, which is sometimes relatively severe, but pneumonia or bronchiectasis often characterized by chest CT.