One of the main reasons Americans enter the emergency room is to evaluate and treat skin tears, deep cuts, or tears. In fact, about 8% of all emergency room visits have incisions; 9 million lacerations are treated each year in the United States

Bleeding wounds can be particularly traumatic for people who cannot control their wounds by applying pressure or placing bandages at home. The situation has become more complicated due to the fact that millions of Americans use blood thinners to prevent strokes or treat blood clots. These blood thinning effects are not easily reversed, and seemingly harmless patients may require a high level of care in the emergency room.

It is not surprising that my patient tried various home remedies to control bleeding before deciding to come to the emergency room. One of the most interesting things I have seen is filling coffee grounds into bleeding wounds.

The patient could not give the reason why he thought it was effective, but he heard from his family that he should try it. Sure enough, when I saw him in the emergency room, the bleeding had stopped. Scientific research or clinical trials exploring the benefits of using coffee grounds to control bleeding are limited. Compared with other medical myths and family remedies, I can't find any important cultural or historical motivation to use it, but it does appear as a local practice of wound healing in Southeast Asia.

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So why do coffee grounds help control bleeding? The caffeine in coffee is a known vasoconstrictor, or a substance that reduces blood flow. In the emergency room, we injected the powerful vasoconstrictor epinephrine and the local anesthetic lidocaine to control bleeding from the wound. A study I found did show that blood flow to the fingertips of coffee drinkers decreased. However, it is not clear whether the caffeine in coffee grounds for external use produces the same vasoconstriction effect.

It is more likely to control bleeding by directly dressing the wound with coffee grounds. This is similar to what we advise people to do at home and what we do in the emergency room; use sterile gauze to press directly on the wound for 15 minutes. It is also possible that the coffee grounds have absorbed some of the exudate and it seems that the bleeding is under control.

So, should you wrap the bleeding wound with coffee? Although the benefits of drinking coffee on a regular basis are increasing—for example, it reduces the risk of colon cancer and heart disease—but I don’t recommend putting coffee grounds or other unsterile substances into the wound.

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The main goal is high-pressure washing to remove dirt and other foreign objects to minimize infection, and then press hard for 15 minutes. For smaller cuts and wounds, this should be sufficient. After the bleeding has stopped, check the wound. If it is superficial, place an antibiotic cream on the wound and secure it with a bandage.

When should you seek medical attention in the emergency room? If the wound is deep or contaminated, bleeding cannot be controlled, or if you take blood thinners, you may need imaging, suture repair, or help reverse the bleeding. Those with diabetes or weakened immune system, wounds or bites in high-risk areas of the face, hands or feet may need antibiotics. If it has been more than 5 years since the last vaccination, it is best to get tetanus vaccination.

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Michael Daignault, MD, is a board-certified emergency physician in Los Angeles. He studied Global Health at Georgetown University and obtained a medical degree from Ben Gurion University. He completed emergency medicine residency training at Lincoln Medical Center in the South Bronx. He is also a former volunteer for the United States Peace Corps. Find him on Instagram @dr.daignault