You may have a trigger thumb. This condition, otherwise known as trigger finger or stenosing tenosynovitis, commonly affects the two fingers essential to the gripping gesture - the index finger and ... the thumb.
A blocking finger, whatever the cause, is never normal. The first step is to assess the onset of symptoms and determine whether the issue results from trauma (fall, sprain or tendonitis). When the thumb is involved and the symptoms are not the result of an injury, a trigger finger, or rather a "trigger thumb" is a likely diagnosis.
Trigger finger / thumb occurs when the tendon that allows the finger to flex thickens and becomes compressed in its sheath. This constriction interferes with the free movement of the finger and causes it to flex gradually. A distinctive click or "pop" may accompany the lifting of the affected finger. Over time, the situation may worsen and the finger may become stuck permanently. If left untreated, a trigger thumb can permanently impair an individual's motor skills.
Call on the expertise of a hand specialist to obtain an accurate diagnosis and find the right treatment plan for you.
The folding of the thumb may, less frequently, be the manifestation of Dupuytren's contracture. The latter pathology is distinguished by the previous appearance of bumps (nodules) and cords in the palm of the hand. Dupuytren’s disease, unlike trigger finger, does not result in a painful click. It is also worth noting that trigger finger is more common in women while Dupuytren's contracture predominantly affects men.