What should you know about proximal phalanx pain in the thumb?

The proximal phalanx is the thumb bone between the knuckle and the end joint. Pain there can follow a knock, a jammed thumb, repetitive gripping, a small ligament strain, tendon irritation, or an injury involving the bone or joint. Tenderness, bruising, swelling, reduced motion, or pain when pinching provide useful clues. Pain closer to the wrist and thumb side can also occur with De Quervain's tenosynovitis, which is a different tendon condition.

Stop the activity that caused the pain and remove rings or tight items if swelling is developing. Protect the thumb in a comfortable neutral position, use a wrapped cold pack for short periods, and keep the hand raised when it is swollen. Avoid forceful gripping, twisting, or repeatedly testing the painful movement. A clinician may recommend a thumb support, an examination, or imaging depending on the mechanism and findings. Do not tape a visibly deformed thumb tightly or try to straighten it yourself.

Obtain prompt assessment after a fall, direct impact, sudden pulling injury, or a thumb that is crooked, unstable, numb, pale, or very swollen. Urgent care is appropriate if you cannot move the thumb, pinch, or hold an object, or if pain is severe and escalating. Arrange a routine review when symptoms persist, recur with gripping, or interfere with work and daily tasks.

Which structure is tender: bone, joint, ligament, or tendon? Do I need an X-ray or another test? Should I use a splint, and for how long? Which thumb movements are safe while it heals?