Brief Answer:
it can be due to bursitis, mild pain killer & antiinflammatory agent

Detailed Answer:
Hi XXXXXXX
Welcome
I have gone through your query and do understand your concern.
Since when you are facing this problem?
Is there any history of injury?
Based on the little information I feel it might be due to inflammation of the joint capsule or bursitis.
You need to start with mild pain killers and anti inflammatory agent like ibuprofen and avoid lying on the painful side.
Avoid all the painful activities of the hip.
Doing a hot fomentation will also help in reducing the inflammation. You can apply analgesic gel or spray to the affected area.
In case the pain is persistent or increases then do consult an orthopedician for prescription medicines like muscle relaxants after proper investigations. (An MRI scan of the hip joint is the best investigation to detect such soft tissue abnormalities)

Hope this helps
Take care

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