Thank you for your question.
I am Dr Saha, I shall try my best to help you.
There are a few possibilities.
Pain behind knee can be due to muscle strain, inflammation of tendons or tendonitis.
There can be cyst formation commonly called Baker's cyst.
Arthritis, ligament or meniscus injury can be there.
A clot in the vein can also cause pain here.
I would suggest to take an examination by doctor.
A few tests like ultrasound, blood work for arthritis, metabolic panel would be needed.
Till then, you can take tylenol for pain.
I hope this information helps.
If there’s anything else I can do, please let me know.
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