Can Swallowing Blood From a Nosebleed Cause Black Stool?

There are several reasons that a person can have a stool that is black, with the most common being from a food or a supplement (such as Oreo cookies or iron pills). When a stool is black because there is blood in it, it is called melena. The black color is one sign that the blood is coming from somewhere high in the digestive tract, like the stomach. Blood that comes from lower in the digestive tract (such as in the colon or from hemorrhoids) may still appear red and cause bloody stools, blood on the stool, or blood on the toilet paper.

Black Stools From Nosebleeds

While it's not very common, it is possible that a nosebleed can result in a stool that appears black. A very severe nosebleed that results in a person swallowing a lot of blood could cause black stools. The blood makes it all the way through the digestive system and appears black or dark by the time it is eliminated from the body.

People who have black stools that aren't from an obvious food or supplement choice or haven't had a recent, severe nosebleed should have their stool checked out by a doctor. Even someone who has had a recent nosebleed, if it bled enough to cause black stools, should also seek medical care. The amount of blood loss could be a concern and the reason for such severe bleeding should be investigated in case it is from a disease or condition that might occur again.

What Is a Nosebleed?

A nosebleed, which is also called epistaxis, is a common occurrence, especially in children between the ages of 2 and 10 and adults between the ages of 50 and 80. Most nosebleeds are not serious, and while they can happen repeatedly, they typically are treatable at home. Nose-picking; trauma to the nose; and dry, warm air that dries out the mucus membranes are some of the common reasons that people have nosebleeds.

Types Of Nosebleeds

Most nosebleeds originate in the front of the nasal cavity and are called anterior epistaxis. This causes the blood to drip out of the nose. A nosebleed from the back of the nasal cavity, or posterior epistaxis, is more serious. Posterior epistaxis may produce bleeding from the front of the nose, but it can also occur without any visible blood, which may make it difficult to diagnose. Posterior epistaxis could cause significant bleeding, which puts a patient at risk for anemia, black stools, and even aspiration of blood.

Common, uncomplicated nosebleeds are often treated fairly effectively with compression: pinching the nostrils together. While sitting or standing, first tilt the head down, towards the floor. Next, pinch the nostrils together gently and hold for several minutes. Avoiding blowing the nose for a time after the bleeding has stopped can help prevent the bleeding from happening again. (Holding the head back or lying down to stop nosebleeds is no longer recommended.)

Severe nosebleeds, however, may need treatment by a doctor in order to get the bleeding to stop. Some of the things a doctor might do for a serious nosebleed are cauterizing (applying heat to) the nostrils or packing the nose with gauze to stop the bleeding. There are other treatments that might be used when the nosebleeds are happening often and won't stop. It's also important to determine the reason for the nosebleeds, because if the cause is found, it may be possible to stop them.

The Bottom Line

If a serious nosebleed has happened recently, it could be the reason for stools to be black in the day or two following. However, black stools shouldn't go on indefinitely, especially if one is not eating black or other dark-colored foods that can explain away the color. Recurring black stools, especially those that smell bad, should be investigated by a physician. It could indicate bleeding in the gastrointestinal tract and may require treatment.