She was not, I was told, in the hospital portion of the house with the fever patients; for her complaint was consumption, not typhus: and by consumption I, in my ignorance, understood something mild, which time and care would be sure to alleviate. (Jane Eyre)
Does ‘understood’ take ‘something’ as its direct object, or is its object – it (consumption) – dropped? (If the former is right, what's the meaning of understood, then?)