Uh Oh.. Is That Blood?
- Andrea Koo
- Jun 17
- 5 min read
Audience: Middle and High School Students
Bleeding may be natural, but not all bleeding is the same: whether it's a paper cut or a more serious injury, knowing how to manage bleeding can make all the difference between a minor mishap and a medical emergency. At the center of it all is the cardiovascular system, a complex network that keeps the body alive by delivering oxygen and nutrients while removing waste. Your blood itself is important too–it’s not just a red liquid; it's a life-sustaining fluid that plays a crucial role in immunity, temperature regulation, and healing. When bleeding occurs, it's a signal that the cardiovascular system has been disrupted, and quick action is needed to protect it. Understanding the implications of bleeding injuries, the critical role of the cardiovascular system, and ways to treat different kinds of bleeds might just help you save a life.
In order to understand blood, we first have to understand the cardiovascular system. Also called the circulatory system, it consists of your heart, blood vessels, and your blood. The heart works as a pump: with two atria (upper chambers of the heart) and two ventricles (lower chambers of the heart) and many, many entrances and exits, it works to pump blood into your blood vessels (arteries, veins, capillaries—we’ll go into these later) to bring your cells what they need, such as oxygen, and take away what they don’t, such as carbon dioxide.
This blood is circulated around your body, working with the lungs to exchange oxygen and carbon dioxide and making sure every part of your body receives what it needs. Your blood is made up of red blood cells (RBCs, erythrocytes), which have hemoglobin that can bind to oxygen; plasma, a mixture of water, sugar, fat, protein, and salts that facilitate the movement of red blood cells; white blood cells (leukocytes), which protect the body from infection; and platelets (thrombocytes), which help the blood-clotting process so that if you were to get cut, you wouldn’t bleed forever. Blood-clotting, also known as hemostasis, is a process that incorporates blood-clotting factors like platelets to try to reduce blood loss and prevent excess loss of blood. The lack of these blood-clotting factors is known as hemophilia, a hereditary bleeding disorder that can be life-threatening: if the bleeding isn’t controlled quickly, even minor injuries can lead to excessive blood loss and cause serious issues.
Your three main blood vessels are arteries, which bring blood away from your heart and to your organs and body parts; veins, which bring blood back into your heart; and capillaries, which are tiny vessels that connect arteries and veins, facilitating the exchange of oxygen, nutrients, and waste products between blood and tissues. These three types of blood vessels work in tandem to work as the transportation system of blood, carrying it from the heart to the rest of your body back to the heart again.
Now, there are varying degrees of types of bleeds; medically, bleeds can range from punctures to abrasions to lacerations. You see it in your daily life as well–a papercut, a scrape on the knee, or a gash from something sharp can all count as bleeding injuries, but raise different levels of concern. So it’s important to be able to recognize the types of bleeds and how to treat them!
Capillary bleeds: These bleeds are the least life-threatening. Often caused by small cuts or abrasions, the blood oozes out slowly. While capillary bleeds may be painful (we all know how the smallest paper cuts hurt the most), they rarely pose a serious threat to health and can usually be controlled with basic first aid like applying pressure or with a BandAid.
Venous bleeds: Venous blood is darker and flows steadily. Though venous bleeds are generally less urgent than arterial ones, they can still be dangerous if not controlled and cause significant blood loss. To treat this, use direct pressure (preferably with something sterile, or clean, but in emergencies, you can use your fingers to press on the wound) and wrap it with gauze or a cloth.
Arterial Bleeds: These are the most serious types of bleeding. Arterial blood is bright red and it spurts out as if being pushed out forcefully in pulses—because it is. Blood will spurt from the wound every time the heart beats and pumps blood through the vessels. Arterial bleeds can be life-threatening because of the rapid and heavy loss of blood, and immediate attention is required. To treat this, apply direct pressure with a clean cloth or your hand, wrap it with a gauze or a cloth, and elevate the body part if you can. If the blood is still spurting through, you may be able to find and apply a tourniquet, a device used to compress the limb above the wound to stop arterial bleeds. Tourniquets should be placed 2-3 inches higher (closer to the heart) than the bleeding site, but never over a joint. If there are no professional tourniquets, you may be able to tightly tie a cloth and secure it with a pen. The goal is to stop the bleeding, so tie it as tight as you can until the blood stops spurting.
Loss of blood and damage to the cardiovascular system can lead to severe complications, including shock, organ failure, and even death, because your cells won’t be getting the oxygen that they need to function properly. Shock refers to a state where the injured person no longer has enough blood circulating around their body, which is a life-threatening emergency. This can quickly deteriorate (or decompensate) into really critical conditions, so work as quickly as you can when dealing with serious bleeding emergencies.
If you’re interested in learning more about bleeding injuries, their implications, and how to deal with them, search for first aid training session guides on the Web or sign up for a class with your local American Red Cross organization. These resources can provide hands-on demonstrations and expert advice on how to recognize different types of bleeding, apply pressure effectively, use tourniquets when necessary, and know when to seek emergency help. If you’re dealing with what you think is a serious bleed, trust your gut feeling and call for help.
Here are some links you may find helpful!
The next time you walk around the halls of your school or around your workplace, always notice and keep in the back of your head where the first aid and/or bleeding control kits are. These kits are often in public places, and more states have begun to mandate their implementation in schools. And if you ever do come across a bleeding injury, keep calm and trust what you’ve learned. Remember: your goal is always to stop the bleeding, so although certain tactics are preferred, do whatever you can manage in an emergency to save someone’s life.
Bibliography
“Bleeding.” Better Health Channel, https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/bleeding. Accessed 9 April 2025.
“Blood Basics - Hematology.org.” American Society of Hematology, https://www.hematology.org/education/patients/blood-basics. Accessed 9 April 2025.
Guide, Step. “Severe bleeding: First aid.” Mayo Clinic, http://mayoclinic.org/first-aid/first-aid-severe-bleeding/basics/art-20056661. Accessed 9 April 2025.
“Hemostasis: What It Is & Stages.” Cleveland Clinic, https://my.clevelandclinic.org/health/symptoms/21999-hemostasis. Accessed 20 April 2025.
“How Your Circulatory System Works.” Cleveland Clinic, https://my.clevelandclinic.org/health/body/circulatory-and-cardiovascular-system. Accessed 9 April 2025.
“Understanding Bleeding Response.” MedicTests, https://medictests.com/units/the-physiological-response-to-bleeding. Accessed 9 April 2025.
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