「具合はどうなんですか？」「ああ、うん・・・少し脱水症状が出ているかな」

「？」「、・・・」

"How are you feeling?" "Ah, yeah… I think I'm a little dehydrated."

Literal

Condition [topic-は] how [explanation-な] is? / Ah, yeah... slight dehydration-symptoms [subject-が] are-appearing [I-wonder-かな].

具合はどうなんですか uses なんですか rather than plain ですか — the のだ/んだ construction seeks or offers explanation, softer and more engaged than a bare question. 出ている with 症状 is idiomatic: symptoms 'come out / appear,' not 'show up' literally. Final かな is the speaker pondering aloud, hedging slightly ('I wonder if / maybe'). The subject 脱水症状 is marked with が because it's new information answering the question.