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Finger Injuries (cont.)

Finger Injuries Causes

A finger may be injured by a direct blow or cut. Many injuries are work-related. The finger may also be jammed, twisted, or stretched playing sports. Animal bites are another common cause of finger injuries.

Jammed finger

  • A direct blow to the tip of a finger can cause tendon or ligament damage, as well as fracture or dislocation of the bones.
  • If the side ligaments are torn, the patient may have pain on the side of a joint, and the joint may be loose.
  • If the ligament on the bottom of the joint (called the volar plate) is torn, the patient may have pain and looseness on the underside of the finger.
  • If a tendon is torn away from its attachment, the patient may be unable to completely bend, straighten, or grip with the finger (or thumb).
  • Several common kinds of injuries that can result from jamming a finger:
    • Skier's (gamekeeper's) thumb: Torn ulnar collateral ligament (the ligament between your thumb and palm in the web space of the thumb and hand), often caused when a skier falls on his or her pole with an open hand.
Picture of Skier's (gamekeeper's) thumb. The ulnar collateral ligament is torn, causing the joint to be loose.
  • Mallet (or drop or hammer) finger: Extensor tendon (the tendon that is on the back or "dorsum" of your finger responsible for extending the finger straight) torn away from the distal phalanx (bone in the end of your finger). This causes the tip of your finger to sag and not completely straighten out.
    Click to view original file
  • Boutonniere deformity: The stabilizing portion of the extensor tendon (the tendon that is over the backside of your finger) is torn between the proximal and middle phalanges (the closest and middle bones of your finger). This causes an inability to straighten the joint between the proximal and middle phalanges.
    Click to view original file
  • Swan neck deformity: Volar ligament (ligament on the palm side of your finger responsible for flexing your finger) torn between the proximal and middle phalanges. As this injury heals, the ligament gets lax and the finger bends in a characteristic "swan neck" pattern.
    Click to view original file

Fingernail injuries

  • The nail bed, which is the supportive tissue underneath the nail, can be damaged by a cut or blow.
  • Sometimes this leads to a collection of blood under the nail, called a subungual hematoma.
  • Subungual hematomas can be very painful and sometimes need to be drained.
  • If the nail is severely damaged, it may need to be removed.
Picture of Nail bed laceration with subungual hematoma


  • Animal bites can cause tissue damage and also can lead to serious infections if not treated properly.
  • A human bite would is often more serious than an animal bite would. It usually happens from punching someone in the mouth with a closed fist (called a "fight bite"). These wounds require thorough cleaning and often antibiotics.


  • A paronychia is an infection in the area where your fingernail attaches to your finger.
  • It often starts after minor trauma such as a hangnail or nail biting.
Medically Reviewed by a Doctor on 3/3/2015

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Finger Injuries - Causes

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Jammed Finger »

The layman's term "jammed finger" often refers to injuries that are incurred around the proximal interphalangeal (PIP) joint of the fingers

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