Hard small pea sized lump behind knee/top of calf

I have noticed a small pea sized lump just below the crease on the back of my knee. After having a prod around it seems to be attached to what feels like a tendon which is running from the inside back of my knee down into my calf muscle.

It is not visible to the eye but it is more noticeable after walking around for a bit or after doing exercise. It isnt painful at rest but can be a bit tender after walking

The tendon in question i am unable to feel on my other knee so it seems like it is inflamed and it nearer the surface.

Other symptoms are tightness in the region and now and again i get a rubbing sensation as if this tendon is rubbing over something

Any ideas?

Could be a ganglion? Might be worth touching base with your gp. Good luck!

Thanks I will book a visit to my gp.

The lump is less noticeable today but the tendon still feels sore. Can someone tell me what this tendon is called? It seems to run from the medial back of the knee and down at an angle towards the centre of the calf

Baker's Cyst maybe?

Try to google some pictures of it and compare it with yours. Usually this cyst is a sign that something is happening inside the joint. (Commonly inflammation and irritation of the internal knee structures, capsule etc.)