This article discusses the types of injuries that might require stitches, explaining when wounds can and cannot be helped by stitches. It also lists reasons to contact your doctor whether or not you have a wound sewn up.

To close a wound to promote healing and discourage infectionTo reduce scarring

Let’s look at the second reason first. If the wound is in an area where scarring would be obvious and the wound is deep enough to see the fatty tissue under the skin surface (the subcutaneous tissue), then getting stitches may allow you to have a less obvious scar. Talk to your doctor if you’re concerned about scarring.

The first reason is more complicated and requires a bit more understanding of the types of wounds, how they are treated, and possible infections.

There are several types of open wounds:

Lacerations: This is what we are thinking of when we say “cuts. " Lacerations are simple breaks in the skin. Incisions: Incisions are surgical wounds, which are usually made by a scalpel. These are similar to lacerations but have very smooth edges. Punctures: It’s hard to tell a puncture from a laceration if the item that made the wound is big enough. Lacerations tear through the skin, while punctures go in and come back out. If the item that made the puncture is still embedded, it’s called an impaled object. Avulsions: These are torn sections of skin, either a flap that’s open on three sides or torn away completely. Abrasions: These are scratches. The difference between an abrasion and an avulsion is the depth. Abrasions leave the skin mostly intact while avulsions remove the skin entirely.

Any open wound in a person with diabetes Animal or human bites (for open wounds) Dirt that won’t come out of the wound A wound in which you can’t close the edges Uncontrolled bleeding—call 911

To determine if stitches are needed, look at three things:

Depth: Is the wound deep enough to see the subcutaneous tissue (which is yellowish and fatty)? If so, the wound is deep enough to get stitches, but it still may not need them. Width: Can the wound be pulled closed easily? If the wound is gaping and cannot be easily pinched closed, then it will need stitches to hold it closed long enough to heal correctly. Location: Wounds on areas of the body that stretch and move a lot will need stitches more often than those on areas that do not move as much. For example, a wound on the forearm will not move as much as a wound on the calf.

Ultimately, if you’re concerned about the wound and unsure whether it needs professional attention, then see a doctor.

Only cuts and puncture wounds that are deep enough need to be stitched by a doctor. You might need to see a doctor even if you don’t need stitches, though, especially if you have diabetes. Other situations in which you should see a doctor regardless of whether you need stitches include being bitten, dirty wounds, and wounds that won’t close or stop bleeding. Talk to your doctor about whether a tetanus shot is needed as well.