Surgical or traumatic wounds require closing. Sutures are medical tools that help close a wound. They reduce the risk of infection and support the healing process.

For example, a dentist who has to remove a large tooth might place a suture in the gums. Similarly, a surgeon removing the appendix may place sutures in the abdomen.

Sutures can be internal, external, or both. They may not be visible. Sometimes, a doctor must remove the sutures after a certain time. However, many types of sutures dissolve on their own.

Sutures typically involve a needle to stitch up wounds. A surgeon applying a suture will choose the material and suture type based on many factors, including:

  • the area that requires suturing
  • the size of the wound
  • the patient’s medical history and allergies
  • which material is least likely to cause complications or scarring

Read on to learn more about what to expect if a person needs a surgical suture. This article discusses the different suture types, materials involved, techniques, and how to care for them.

Close up of a surgeon's hands while they are suturing a wound -1.Share on Pinterest
JazzIRT/Getty Images

A surgeon will likely consider the suture type, needle, and size to use when closing a wound.

Types of suture

Surgeons classify sutures according to several categories:

  • Absorbable vs. non-absorbable: Absorbable sutures lose strength with time, causing them to fall apart. The body eventually absorbs them. The material of the suture often influences whether it is absorbable. These can include materials such as poliglecaprone 25 and polyglactin 910.
  • Multifilament vs. monofilament: Monofilaments use a single strand and pass through tissue easily. They also tend to retain their original shape. Multifilament sutures use multiple strands that are joined together like a braid or rope.
  • Natural vs. synthetic: Sutures may be made from synthetic material or natural fibers, such as animal tissues. A surgeon will choose the best option based on the location of the suture.

Surgeons will choose suture properties most suitable for the type and purpose. For example, they may opt for monofilament absorbable sutures if there is a high infection risk.


Because sutures enter the tissue, a surgeon must use a needle to apply them. Sometimes, the technique can resemble sewing.

The needle a surgeon chooses partially depends on the type of suture and its thickness. Suture needles usually have a cutting tip or a taper tip. This is less sharp when going through the tissue. Manufacturers assign a size number and letters to each needle type.

A surgeon’s expertise and comfort with various tools may play a role in the needle they choose.

Suture sizes

Each suture or stitch can vary in size depending on the suture material a surgeon chooses. Some suture materials are larger than others, such as multifilament sutures. Also, larger sutures generally require larger needles.

Suture materials are numbered based on the size of the strands. Generally speaking, the larger the suture number, the larger the suture diameter. However, suture numbers followed by a -0 decrease in size at the number increases.

The wound itself will determine how many sutures a person needs and the size of the area that needs suturing.

Surgeons may employ various techniques to suture wounds. The suture material, wound size, and wound location can influence which technique a surgeon uses.

Some examples of suture techniques include:

  • Vertical mattress suture: Surgeons often choose this technique for skin that moves or has poor support. It involves inserting the needle about 5 millimeters from the wound edge and exiting on the other side. The needle is then reinserted for the second time closer to the edge of the wound.
  • Simple interrupted suture: This basic suture technique is appropriate for many wound types. The surgeon inserts the needle on one side of the wound and then exits on the other. Sutures are 2–5 mm apart.
  • Horizontal mattress suture: Similar to a mattress suture, this technique involves drawing the suture across a wound.
  • Subcuticular suture: This suture avoids marks on the skin’s surface. Instead, it places the stitches deep in the dermis, or the second skin layer.

Different sutures require different care, so getting clear guidance from the person who applied them is important.

The following tips can help keep sutures healthy, reduce pain and inflammation, and lower the risk of infection:

  • Do not pick at or touch the sutures.
  • Avoid soaking the sutures.
  • Keep the wound dry for the first 24 hours and minimize water exposure afterward. A doctor may recommend covering the wound with plastic.
  • Do not apply anything to the wound unless a doctor recommends doing so.
  • Call a doctor if the wound turns red, hot, or painful.
  • Call a doctor if a person has a fever, the wound smells, or the wound or suture is oozing a lot.

Sutures that dissolve on their own do not require removal. Small pieces may fall out over time. A person should not pick at them or attempt to pull them out.

If sutures require removal, a doctor will likely do so. They will also be able to advise on how long a suture needs to be in place.

Removing the sutures involves cutting or tugging them directly instead of the skin itself. As a result, removal should not hurt, although a person may feel a tugging sensation. If the wound is still tender, the pressure on the wound may be uncomfortable or even painful.

Ask a doctor about pain relief options if the wound is still painful.

Sutures are the threads that close a wound, while stitching is the closing process. The two together achieve the same goal, and most people use the terms interchangeably.

Sutures come in many sizes, shapes, and materials. They may be invisible or cover a wide area of the skin.

Depending on the type, a person may never notice their sutures absorbing or falling out. Alternatively, they may need to seek medical care for removal.

People who need sutures or have recently had surgery should discuss appropriate suture care and signs of complications with their surgeon.