How does lupus affect lungs?

See below: It can affect the lungs in a variety of ways including pulmonary embolism, interstitial lung disease, pleurisy, pleural effusions, and pulmonary hyptertension.

Several ways: The most common problem is pleurisy (pain on taking a breath) due to inflammation of the covering layer of the lungs. Lupus patients can also have infiltrates within the lungs, blood clots (pulmonary emboli), or bleeding into the lung tissue. Aside from pleurisy, most of these problems are very uncommon.