While you're probably familiar with veins and arteries, capillaries may warrant a quick definition. Capillaries are tiny blood vessels linking arteries and veins that transfer oxygen and other nutrients from the blood to all body cells and remove waste products.

Capillary bleeding has the classic appearance of a road rash type of wound. Anyone who has fallen off a bike or while playing sports likely has some experience with this type of bleeding injury.

Capillary bleeding distinctions are:

  • The blood tends to ooze or bubble up on the surface of the wound
  • The pressure is very low and will usually clot on its own or with minimal pressure
  • The blood is mixed with serous fluid

Serous fluid is a yellowish liquid that is made up of proteins and water. It's the same fluid that fills a burn blister and is the body's attempt to heal the wound.

How to Provide Care

Capillary bleeding is usually not a concern in healthy people. The blood vessels are quite small, and the pressure is minimal. Some things to keep in mind with capillary bleeding are:

  • Because it affects the epidural layer where the nerve endings are located, it can be more painful than other types of bleeding injuries
  • Infection is likely to be the biggest area of concern
  • Thoroughly cleaning the wound is the greatest weapon against infection, particularly if the victim fell on a dirty surface

As always, the first thing you should do is make sure the scene is safe. After that, proceed with the following steps.

  • Put on latex-free gloves if available or wash your hands thoroughly using soap and water or a sanitizer of some kind, preferably with alcohol.
  • Remove any visible debris from the wound – dirt, sand, pebbles, and shavings of glass or metal.
  • Blot the area with a dressing pad and apply direct pressure if the bleeding hasn't stopped on its own.
  • Thoroughly clean the wound with soap and water.
  • Apply an over-the-counter triple antibiotic to the area using a clean dressing pad.

Pro Tip 1: When cleaning off debris from the wound, if you notice that those things are embedded into the wound, the victim will need to make a trip to the ER, where the medical staff will probably need to numb the area before removing the debris. The nerve endings could be quite raw, and it's important to keep in mind that the victim may be in a good deal of pain.

Once the wound is cleaned and the antibiotic has been applied, put a fresh dressing pad over the area. Make sure it's large enough to cover the wound completely with room to spare on all sides.

Using medical grade tape, if you have it, hold the dressing pad in place with a couple strips of tape or however much is needed. Let the victim know that he or she can replace the pad with a large band aid after a day or two.

Pro Tip 2: It's important to help the victim understand what the signs of infection are, as this is likely to be the biggest threat with capillary bleeding wounds. Signs of infection include:

  • Puss oozing or draining from the wound
  • The wound becomes puffy and more painful
  • A wound that begins to turn red around the site

Warning: Capillary bleeding is usually not a life-threatening injury, but infections could be. If the victim notices any of the above, it's important that he or she go to the ER or their doctor to avoid the chance of serious infection. However, keeping the wound area clean is often enough to avoid this complication.

Also let the victim know what a healthy outcome of capillary bleeding looks like:

  • The wound will begin to scab over after 48 – 72 hours
  • After a couple of more weeks, it should be completely healed as the scab begins to fall off

A Word About Life-Threatening Bleeding

While capillary bleeding is often very easy to control, it's important to understand the concept of the Golden Hour – the critical first hour after a traumatic bleeding injury has occurred.

During the Golden Hour:

  • The risk of shock is at its highest
  • Extensive blood loss can quickly result in death
  • Quick action and proper intervention will result in the victim's best chance of survival

As all bleeding injuries occur from arteries, veins, and capillaries, it's important to understand what a life-threatening bleeding incident looks like.

  • Blood that is spurting out of a wound.
  • Blood that won't stop coming out of a wound.
  • Blood that is pooling on the ground.
  • The victim's clothing is soaked with blood.
  • Bandages that are soaked with blood.
  • Loss of part, or all, of an arm or leg.
  • Bleeding in a victim who is confused or unconscious.

If you experience any of these situations while providing care, be aware that these can be life-threatening, and you should call 911 immediately and get EMS involved.

Capillary bleeding is often the least severe type of bleeding injury, but don't get lulled into a false sense of security. Any bleeding situation can become serious. And it deserves repeating that with capillary bleeding, it's especially important to clean the wound well to reduce the chances of infection.