The sticking and popping associated with trigger finger result from a constriction of the protective covering that wraps around the tendon in the finger. Underneath this sheath is a substance called tenosynovium, which releases a lubricating fluid that helps the tendon move smoothly. However, if the tenosynovium becomes inflamed, the tendon cannot move freely, making it more prone to catching or locking. When this happens, the inflammation worsens, making the problem even worse. If this cycle continues for a long period of time, it may develop into fibrosis (scarring and thickening of the affected tissue) or may lead to the development of nodules. It is more common in women, diabetics, and people whose jobs or hobbies require them to repetitively grip their hands. Other symptoms of this condition include stiffness in the affected finger (especially in the morning) and/or the presence of a tender bump at the base of the finger. Most people with trigger finger experience it in their dominant hand, typically in the thumb, middle finger, or ring finger. While most cases of trigger finger do not need urgent treatment, you should seek immediate medical attention if the finger joint becomes hot or inflamed as this could be a sign of infection.