What Causes Severe Pain Behind The Knees?
Please go in to ER
Detailed Answer:
Hello and welcome,
It is possible that this could be a superficial phlebitis or a deep vein thrombosis. It can also be a strain of the muscles or ligaments of the knee. Without being able to examine it, and with severe pain, I think you should go in to be seen in the ER.
Phlebitis is when there is a clot or inflammation in a superficial vein. There is usually tenderness at the site, and swelling. Treatment is NSAIDS, leg elevation, and heat.
A DVT is a clot in a deep vein and there is sometimes swelling below the level of the DVT. While phlebitis is not risky, a DVT can cause a pulmonary embolus so it is treated usually with medication to dissolve the clot. A DVT is diagnosed by doing an ultrasound or a D-Dimer test.
So, I advise you to go in to see what is going on.
I hope this information helps.