Brief Answer:
X-rays are a must.

Detailed Answer:
Hi.
Thanks for your query, albeit short.
Please give additional information for me to assist you better.
Your age and gender please.
When did this happen?
Which area is most affected?
Please post clear and focused photos.
Is walking painful? Or even movement of leg painful?

As per your history of slipping from stairs - redness, swelling and pain indicate a possibility of fracture which should be confirmed or ruled out by clinical examination and X-rays. This will give proper diagnosis so that a proper management can be done.
Till then take full rest, no movement of the affected leg at all. Put a splint or so to make the area immobile.

Please give feedback.
I hope this answer helps you.

With Regards.
Dr T Chandrakant.

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