A trigger digit sufferer will experience discomfort or pain in the palm of the hand at the base of the affected finger(s) and often a clicking feeling when moving the digit, especially when bending and straightening. The digit may, in fact, get caught down in the palm, and it may be necessary to pull it straight again with a painful click. In a milder form of this condition the clicking and catching down in the palm may be absent, but the discomfort is present. Trigger finger or thumb can come on gradually, or occasionally rapidly, and may resolve spontaneously over time or remain indefinitely without treatment.
Who gets triggering?
Trigger finger is a very common hand condition affecting females and males of all ages. Infants and middle-aged women are particularly prone, and it is more common in people who have diabetes. It is quite common in patients who have carpal tunnel syndrome.
What causes triggering?
The flexor tendons that bend your fingers run within a tunnel called the fibrous flexor sheath, from the end of your palm into your finger as shown in the diagram below. The mouth of the sheath (A1 pulley) is narrower than the main part of the tunnel. In a trigger digit, a small swelling develops in the tendon which catches in the mouth of the sheath as the tendon glides in and out of the sheath. The clicking feeling represents the swelling catching at the mouth flexor sheath. The cause of the majority of swellings causing a trigger digit is not known, however, fortunately, there is an effective treatment is available.
A trained medical practitioner can diagnose trigger finger by clinical assessment. It is rare for any additional tests to be required although occasionally an ultrasound can provide additional useful information.