It's just a cold. The doctor says it's nothing serious.
4 seconds sound clip from the It's a Wonderful Life (1946) movie soundboard.
You can hear this line at 01:27:08 in the Blu-ray version of the movie.
Quote context
[...]
- Now, go on upstairs and see if little Zuzu wants anything.
- Zuzu? What's the matter with Zuzu?
- Oh, she's just got a cold. She's in bed. Caught it coming home from school.
- What is it, a sore throat or what?
- It's just a cold. The doctor says it's nothing serious.
- The doctor? Was the doctor here?
- Yes, I called him right away. He says it's nothing to worry about.
- Is she running a temperature? What is it?
- Just a teensy one, 99.6. She'll be all right.
- Why did we have to live here in the first place and stay around this measly, crummy old town?
[...]