Hi, one thing is here sure that neither it is due to glands nor due to posture. After going through your problem, pl tell pain is in the elbow or around it, whether there is swelling or not. Mild pain may be due to some infection in the body. It might also be due to anxiety
. Note on thing in females there is anaemia
so pl check your haemoglobin
from a lab. GOOD LUCK for speedy recovery.