How many stairs?
If one walks up steps, especially if overweight
or out of shape, there can be pain in the muscles used most, thigh quadriceps.
If this was a rare outing to climb a lot more steps than usual, then it is unlikely to be a health threat. However, if one is out of shape or walked up steps that typically would not have been a challenge or caused pain, there is reason to see a doctor for eval/ex plan/etc.