Your concern towards your problems are very much justified. Although you have mentioned the problems in quite detail, you have failed to mention the reason for taking lorazepam
. Feeling a specific bodypart warmer than rest of the body parts is very unlikely unless you have some kind of active infection/inflamation going around the specific areas. It is mostly unlikely for lorazepam to cause such kind of symptoms. But all said, its always better to consult a rheumatologist
for an opinion who would like to run a few blood tests and also x-ray your joint. It doesn't seem to be a serious condition.
Hope your concerns are answered.