Most physical wounds produce some drainage. It is common to see blood seeping from a fresh cut, but there are other substances that may also drain from a wound.
In this article, learn about serosanguineous drainage and other types of drainage. When should you see a doctor?
What is serosanguineous drainage?
Serosanguineous drainage may occur when a wound is attempting to heal. It is rarely a cause for concern.
Serosanguineous drainage is one common type of wound drainage. It typically appears as the wound is trying to heal and may have a pale red or pink color.
Serosanguineous drainage may also appear as a clear liquid swirled with red blood. The changes in appearance depend on how much clotted blood is mixed in with the blood serum.
This type of drainage is a sign of healing, and it is not usually a cause for concern when it appears in normal amounts.
Serosanguineous drainage that becomes redder may be an indication of active bleeding, a reopened wound, or a hemorrhage.
Causes of serosanguineous drainage
If a wound gives off serosanguineous discharge, it may be due to damaged capillaries. This is very common in wounds with larger surface areas that need their dressings cleaned.
Old drainage may dry and attach to the dressing or bandage and damage the capillaries close to the skin when it is pulled off.
Injuries that require a person to change their dressings regularly may produce more serosanguineous drainage, though this can happen in wounds of any size.
Other types of drainage
There are a few different types of drainage that may appear on a wound as it heals. Some are part of the natural healing process, but there are times when drainage is a sign of infection.
The following are different types of wound drainage:
Sanguineous drainage is the first drainage that a wound produces. It is the fresh red blood that comes out of the injury when it first occurs. It will thicken as the blood starts to clot.
This initial drainage occurs when a wound is in the first stage of healing, known as the inflammatory stage. Sanguineous drainage may last longer in deeper wounds.
Sanguineous drainage that occurs later on in the wound's healing process may be a sign of further damage to the tissues in the area. This later discharge may happen with larger wounds that require the bandages to be changed regularly. Pulling off a bandage or dressing may result in a wound reopening, causing red sanguineous drainage.
Emergency services should be contacted if bleeding gets worse or does not stop.
Sanguineous drainage that persists or gets worse may be a sign of a hemorrhage. This occurs when deeper tissues below the surface of the skin are damaged and an artery or vein is cut.
If an artery is cut, the blood may appear bright and spurt out of the wound. If a vein is damaged, the blood may be a deeper red and come out steadily.
Small wounds that hemorrhage can be managed by applying direct, firm pressure with a clean cloth. Once the wound closes and the bleeding stops, the area will need to be cleaned and treated, then covered up.
Large or deep wounds that hemorrhage often need treatment from a doctor. If the bleeding cannot be easily controlled, emergency services should be contacted. Anyone who is uncertain about the severity of a wound should seek medical attention.
Serous drainage is composed mainly of plasma. It is often thin and watery and will usually have a clear to yellowish or brownish appearance. Small amounts of serous drainage are normal during the first stages of healing.
Continuous serous drainage may be a sign that there are high levels of bacteria living on the surface of the wound. In these cases, the body is producing extra serum to try and combat the bacteria. Anyone experiencing excessive serous drainage should see a doctor.
While the other common types of drainage are normal to see during the healing process, purulent drainage is not. Purulent drainage is a strong indicator that the wound is infected.
Purulent drainage often appears as a liquid with a slightly thicker, milk-like texture. The color of purulent drainage may vary from a grayish-yellow to green or brown.
Purulent drainage is caused by the number of living and dead infectious cells in the area, as well as the body sending white blood cells in to fight off the infection.
As the infection gets worse, the amount of discharge will often increase. Purulent drainage requires a trip to the doctor for diagnosis and treatment.
As the name suggests, seropurulent drainage is a combination of serous drainage and purulent drainage. It occurs when clear serous drainage becomes tinged with a milky fluid of varying color, similar to that of purulent drainage.
Seropurulent drainage may be an early sign of an infection, but it may also be a sign that an infection is clearing. Anyone experiencing seropurulent drainage should have a doctor diagnose their wound.
When to see a doctor
If the amount of discharge from a wound seems excessive, or if the discharge is thick or milky, a person should speak to their doctor.
Sanguineous, serous, and serosanguineous discharge are all a part of the wound healing process. They help the wound stay lubricated to make healing easier.
These types of drainage will usually appear in the first few days of a wound's healing process and then disappear as the wound scabs over.
Many small cuts or wounds can easily be treated at home or with over-the-counter creams, but there are still times when a trip to the doctor may be necessary.
No matter the type of discharge being produced, anyone who feels they are experiencing too much discharge for the size of the wound should see a doctor. In these cases, there may be an underlying issue or deep tissue trauma that needs to be treated before healing can continue.
Anyone with thick, milky drainage coming from their wound should visit the doctor. This is typically a sign of an infection in the area and will need treatment to avoid more serious complications.
Wounds that give off a foul or unpleasant odor may also require a trip to the doctor. While this may or may not be a sign of an underlying infection, it is better to be safe and seek a proper diagnosis.