Left leg pain that's worse when hanging over a chair or bed. butt cheek hurts too and whole leg aches. driving me mad.

Sciatica shows up: Going from butt, to ankle and has a funny feeling of being 'stretched' but uncomfortable. Best if you can be seen by an osteopathic physician for evaluation, and treatment of your musculoskeletal system to determine the cause ; reduce pain. Your entire spine, hip, sacrum, pelvis, and extremities (arms/legs) will be evaluated, gait analysis too if it is sciatica, it can be easily treated.

Under pressure: Seems if pressure is applied to the back of your leg your symptoms increase. That's where branches of the sciatic nerve are. With the pain you describe in your back, you may have a partially herniated disc, compression fracture, or at least some type of swelling on the nerves exiting your lumbar spine. Back injured recently? New exercise routine? Mva? Lifting? Google r.I.C.E. Tx, call doc.