Potential Outcome of Injuries
Nail gun injuries are highly underreported and under treated. [6, 7] Nails are very sharp, and entrance wounds are small,  so employees will often pull out the nail and continue working, usually only seeking treatment if the injury is deep or they cannot remove the nail. [6, 8] But, reporting the injury, thoroughly cleaning the wound, and seeking medical treatment are very important because of the functional aspects of the nails.
Nail strips are often glued or adhered together with a resin, plastic, or adhesive coating into long strips that feed into the barrel of the gun.
Nails are Adhered Together and Joined With a Paper Coated Strip
When the gun is fired into the wood, the friction heats the glue and melts it. When the nail enters wood, the glue will quickly harden and fuse the nail to provide extra durability. This poses a problem when a nail enters the body, because the melted adhesive will also enter the wound, cool, harden, and fuse. [2, 3, 10] Soft tissues will stick to the coatings, the coatings are not easily removed from the wound, and they are clear and hard to identify. [7, 9]
The body will react to the foreign body and this can cause swelling and infection.  Medical exploration of the wound is often necessary to ensure complete removal of all coatings or adhesives. [2, 3, 9] Additionally, very small pieces of clothing or surface skin can be dragged into the wound upon the nail entrance, and these also aid in the production of infection. [3, 7] Infection is very common if the nail has penetrated a joint. 
Another functional aspect of the nail can also complicate nail gun injuries. Barbs, to improve the grip of the nails in the wood, will hold onto surrounding tissues and vital structures. If the nail is removed incorrectly, more damage can be caused. [1, 2, 10]
X-Ray of Nail Through Hand
Picture Obtained From: I Have a Nail “Stuck” In My Hand 
Focusing on just the hand, the most common site of injury, when a nail penetration occurs, any number of tendons, ligaments, vascular structures, or nerves in the hand can suffer a direct hit from a nail gun injury, or they can be pinched or occluded by the nearby nail.