How to Know If Bleeding Is Serious
Adults have about 5 liters of blood, but how much of that can you lose?
We've all injured ourselves at times (even if it's just a paper cut), but it's important to be able to determine if bleeding is truly severe.
Any kind of loss of blood is serious, and bleeding that won't stop is more serious. Where the blood is from will also make a difference, as a bad bleed from a finger isn't as serious as a bad bleed from the neck. Likewise, spurting blood is more serious than a slow oozing bleed.
Ultimately, if bleeding isn't controlled, people will progress into irreversible shock. This usually happens after losing 2 liters of blood.
Let's talk a little bit more about how you can know if bleeding is serious and what you can do to stop it.
Quick answer: Bleeding is serious when it spurts or pulses (arterial), flows steadily and won't stop with firm pressure, soaks through dressings, pools quickly, or comes with signs of shock (pale, cold, clammy skin, a fast weak pulse, dizziness, or confusion). There are three types, capillary (minor oozing), venous (steady dark-red flow), and arterial (bright red, spurting, most dangerous). Location matters too: limbs can take a tourniquet, while neck and groin wounds need wound packing and pressure, and chest or abdominal bleeding may be internal and needs an ER fast. For any serious bleed, call 911 and control it with direct pressure, a tourniquet, or wound packing. Educational only, not medical advice, call 911 and get trained.
Types of Bleeding and the Level of Seriousness
If you're human then you've probably seen blood before. Most of us have cut our fingers, skinned our knees, or have had a nosebleed at some point. The thing is, even these small bleeds can be serious. Not only that, but many people either overestimate or underestimate how much blood they've lost.
No amount of bleeding should be ignored. That being said, there are some types of bleeding (and conditions) that can cause an immediate life threat. Let's go over a few different types of bleeds.
Types of bleeding (sources):
Capillary bleeding Venous bleeding Arterial bleeding
We'll go over these types of bleeding in more depth.
How Serious is a Superficial (Capillary) Bleed?
Capillary bleeding is usually the least severe. The capillaries are the smallest blood vessels that deliver blood to the tissues throughout the body. Capillary bleeding is common when there is blunt trauma to your skin, such as skinning your knee on the asphalt.
This bleeding is usually more of a slow seep than a flow. Often, all that's needed is to clean the area to avoid infection and to apply a light bandage. If someone is on blood thinners, then there's a chance you'll need to apply direct pressure to stop the bleeding.
Now let's talk about venous bleeding.
How Serious is a Venous Bleed?
A venous bleed is blood from the veins. Now, to understand the severity of capillary, venous, and arterial bleeds, we need to understand the purpose of these blood vessels. Imagine the arteries are like a pressure washer, with pressure behind the flow and the blood has a tendency to spray or spurt out. Arteries are under pressure and carry blood directly from the heart to other parts of the body.
The veins are more like a gentle garden hose and tend to trickle blood instead of spurt. The veins are under low pressure, and they bring blood back to the heart and lungs.
With that being said, a venous bleed can be very severe depending on the location, and it will require super-firm direct pressure to the site of bleeding. Usually, a pressure bandage and firm direct pressure will stop a venous bleed.
How Serious is an Arterial Bleed?
Arterial bleeds are the most serious. Remember what we said in the last section? How arterial bleeds are similar to water spraying from a pressure washer? An arterial bleed will spurt bright red (oxygenated) blood and require super-firm direct pressure right away.
With an arterial bleed from a major blood vessel, a person can lose most of their blood within seconds, so it's critical to give them good first aid. Make sure you know how to apply direct pressure and how to apply a tourniquet if needed.
Now let's go over the severity of a bleed from different sources.
The Severity of Bleeding Based on Site (And How to Stop the Bleed)
In this section, we'll talk about different places you could bleed from as well as different types of injuries and how they bleed. We'll also mention how these bleeds can be treated (first aid) and provide links to more resources on different tools to stop a bleed.
The severity of a bleed based on location:
Hands and arms Feet and legs Neck and Groin Head (skull) and face Chest and Back Abdomen and Internal Bleeds
More details below.
Bleeding from Hands and Arms
Bleeding from the hands and arms can certainly be severe, especially if an artery is severed. Some of the most vulnerable locations are the wrist and the inside of the arm. If you're alone and your arm or hand is bleeding, apply firm direct pressure with your opposite hand. You don't need to wear gloves or have a towel or anything - you can just apply pressure directly with your hand.
If you think you might need a tourniquet, don't hesitate to apply one. Your best bet is to place the tourniquet "high and tight," on your upper arm, even if the bleed is from your lower arm. If you can get to a hospital within two hours, there's a good chance they can save your arm.
Bleeding from Feet and Legs
Bleeding from anywhere on the legs can be severe. There are larger blood vessels in your legs than in your arms, leading to higher pressures and a greater likelihood that a bleed will be life-threatening.
Keep in mind that, on the leg, you might need two tourniquets to stop some bleeds. This could be because the bleeding is that severe, or that the person has a particularly large leg and requires more pressure.
Otherwise, bleeding from the leg is treated with direct pressure, pressure bandages, and a tourniquet if you feel it's necessary.
How do you know you need a tourniquet? If in your mind you think, "Gosh, that's a lot of blood," don't hesitate to apply the tourniquet. The worst-case scenario is that it's a false alarm, and the physicians remove the tourniquet at the ER. Don't worry about specific estimates or anything like that. If the bleeding is bad, act.
Bleeding from Neck and Groin
Bleeding from the neck and groin is tricky because you can't control it with a normal tourniquet. Bleeding from these areas is very serious, especially if the cut is deep. You'll need to hold direct pressure and possibly pack the wound with gauze. Here's some more information on wound packing and how it works to control serious bleeding.
You have to be careful about the person's airway in the neck area. You need to apply pressure to a bleed but be cautious about how you apply that pressure - you don't want to constrict the trachea.
Bleeding from the Head (skull) and face
The head has a lot of bleed vessels, so even small cuts can bleed a lot. If you've ever cut yourself shaving, you've probably experienced this. A superficial bleed to the head should be taken seriously; however, with good direct pressure, the bleeding should stop without causing more problems. If the cut is deeper or involves the face, it's important to go into an urgent care or ER to have it evaluated.
Even if the bleeding from the face isn't serious, if the cut doesn't heal properly it could leave you looking like a pirate!
Bleeding from Chest and Back
Bleeding from the chest and back should be controlled with good direct pressure. If the wound extends into the lung cavity, then you won't be able to control the bleeding from the outside - this is a serious emergency. Be sure to get the person to the hospital as soon as possible.
If there's a hole in the chest cavity, the person might have a sucking chest wound or be in danger of a tension pneumothorax. Keep this in mind when caring for the person.
Abdomen and Internal Bleeds
Bleeding from the abdomen is serious - but what can be more serious is unseen internal bleeding within the abdomen. If someone has a deep open abdominal wound, they will need medical care right away. If someone sustained a hard impact on the abdomen, they might have internal bleeding you cannot see, so they should still be taken to a hospital for evaluation.
Now let's go over some bleeding-related complications.
Bleeding Complications to Keep in Mind
Sometimes, a bleed isn't just a bleed. Let's talk about a few complications to know. This list of complications will help you decide if a "mild" bleed should be upgraded to a "serious" bleed. Some people will have one or more of these conditions.
Bleeding complications:
- Cold/hypothermia: if someone is too cold it can inhibit their body's ability to clot. So if someone is injured, keep them warm!
- Blood disorders/Anemia: People who are anemic already don't have enough hemoglobin in their blood, so any amount of blood loss can be severe.
- Pregnancy: Pregnant women will produce more blood than usual, as a result, serious internal bleeding might not cause changes until later.
- Blood thinners: Even taking a regular aspirin can have an impact on blood loss - keep this in mind when assessing a bleed.
- Infection risks: Finally, all bleeding is dangerous, because an open wound presents an infection risk to the patient and to those caring for them. Keep this in mind at all times.
Now let's go over some final words.
Must-have tools for your first aid kit
It’s time to check your med kit to make sure you have the tools you need to stop a bleed. These are several first-aid kit must-haves to make sure you and your family are prepared. Keep in mind any good bleeding control kit will have a tourniquet and QuickClot gauze of some kind.
Skinny Medic Stop The Bleed Kit
Conclusion: How to Recognize and Stop a Serious Bleed
No amount of bleeding should be taken lightly. If you think to yourself, "Wow - that's a lot of blood," then the bleeding is serious. It's as simple as that. Don't be afraid to apply a tourniquet.
The most important thing is that you know how to apply good super-firm direct pressure to the wound, and that you know how to use a tourniquet.
Remember, bad bleeding can happen fast, so you need to learn how to control it fast. Even though we recommend you call 911, even waiting 3 minutes (and often longer) for an ambulance is too long. Learn to protect yourself.
Be sure to read this article on when you should remove a tourniquet.
Serious Bleeding FAQs
How do you know if bleeding is serious?
Bleeding is serious if it spurts or pulses, won't stop after firm, sustained pressure, soaks through dressings, or pools quickly, or if the person shows signs of shock such as pale, cold, clammy skin, a rapid weak pulse, dizziness, or confusion. Any of these means call 911 and control the bleeding immediately.
What are the three types of bleeding?
Capillary bleeding is minor oozing from small surface vessels and usually stops on its own. Venous bleeding is a steady flow of darker red blood. Arterial bleeding is bright red and spurts or pulses with the heartbeat, it's the most dangerous and can become life-threatening quickly.
What's the difference between arterial and venous bleeding?
Arterial blood is bright red and spurts in time with the pulse because it's under high pressure, making it the most urgent. Venous blood is darker and flows steadily without spurting. Arterial bleeding demands immediate, aggressive control.
When should you call 911 or go to the ER for bleeding?
Call 911 for any bleeding that spurts, won't stop with pressure, involves large blood loss, or comes with signs of shock, as well as deep or gaping wounds, neck, chest, or abdominal wounds, and suspected internal bleeding. When in doubt, treat it as serious and get help.
What are the signs of shock from blood loss?
Shock can cause pale, cool, clammy skin, a rapid but weak pulse, fast breathing, dizziness or weakness, confusion or anxiety, and eventually loss of consciousness. Shock is a medical emergency, call 911, control the bleeding, keep the person warm, and lay them down.
How much blood loss is dangerous?
Losing roughly a liter or more (in an adult) can lead to shock and become life-threatening, and children have far less blood to spare. Rather than trying to estimate volume, act on the warning signs, rapid loss, soaked dressings, and symptoms of shock all mean serious.
Which bleeding sites are most dangerous?
Neck and groin wounds are especially dangerous because major vessels there can't be controlled with a tourniquet and require firm wound packing and pressure. Chest and abdominal wounds may cause internal bleeding you can't see, and head wounds bleed heavily, all need rapid medical care.
How do you stop serious bleeding?
Apply firm, direct pressure to the wound. For life-threatening limb bleeding, use a tourniquet high and tight. For wounds where a tourniquet can't go, pack the wound with hemostatic or plain gauze and maintain pressure. Keep pressure on and the person warm until EMS arrives.
