Adventures in Swedish

Our daughter has an infection. A lump started to form on her neck, below her ear. I called the doctor to find out what we should do. We spoke in Swedish.

"My daughter has a knull on her neck," is what I said.

Pause. "You mean knöl...?" she said.

"OK yeah, knöl."

I know Swedish pretty well. But I can stumble into areas I'm not quite sure of language-wise. Here were two of them: medical terms and swear words. Knöl is the word for lump. Knull is the f-word.