What causes creaky knees?

[mil1234]

My knees sound like an old door when I move them-what causes this? I'm only 21.

[vickster]

Welcome to the forum.
The medical term for creaky knees is crepitus. If you Google it, you should get plenty of hits eg https://www.healthline.com/health/osteoarthritis/crepitus#when-to-worry
If there’s no pain, and given your age, it’s unlikely to be a cause for concern and is very common. If it’s painful, you have swelling etc, see a healthcare professional such as a physiotherapist or doctor.