Eli5: What is the body trying to do when it goes into anaphylactic shock?


Is it trying to fix itself by closing the airways?….Or is it just a reaction and not a defense.

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11 Answers

Anonymous 0 Comments

Anaphylactic shock is a severe allergic reaction that occurs when the body’s immune system overreacts to a foreign substance, such as a food, medication, or insect venom. The body’s immune system mistakes the substance for something harmful and releases chemicals to fight it off, which can cause a number of symptoms, such as difficulty breathing, a rapid heartbeat, and a drop in blood pressure.

In layman’s terms, the body is trying to protect itself from something it thinks is dangerous. But in the process of trying to protect itself, the immune system overreacts, causing a cascade of symptoms that can be life-threatening if not treated promptly.

During Anaphylaxis the immune system release Histamine, which causes the blood vessels to dilate, making the blood pressure to drop and cause the person to feel light headed and dizzy, And also constricts the airways making it difficult to breathe, This can happen rapidly and happen in multiple parts of the body simultaneously.

It’s a medical emergency and requires immediate attention, if you suspect someone is experiencing anaphylactic shock, call for emergency medical services or 911, and administer epinephrine if available.

Anonymous 0 Comments

-From the [Mayo Clinic](https://www.mayoclinic.org/diseases-conditions/anaphylaxis/symptoms-causes/syc-20351468)

> Causes
The immune system produces antibodies that defend against foreign substances. This is good when a foreign substance is harmful, such as certain bacteria or viruses. But some people’s immune systems overreact to substances that don’t normally cause an allergic reaction.

>Allergy symptoms aren’t usually life-threatening, but a severe allergic reaction can lead to anaphylaxis. Even if you or your child has had only a mild anaphylactic reaction in the past, there’s a risk of more severe anaphylaxis after another exposure to the allergy-causing substance.

>The most common anaphylaxis triggers in children are food allergies, such as to peanuts and tree nuts, fish, shellfish, wheat, soy, sesame and milk. Besides allergy to peanuts, nuts, fish, sesame and shellfish, anaphylaxis triggers in adults include:

>Certain medications, including antibiotics, aspirin and other pain relievers available without a prescription, and the intravenous (IV) contrast used in some imaging tests
Stings from bees, yellow jackets, wasps, hornets and fire ants
Although not common, some people develop anaphylaxis from aerobic exercise, such as jogging, or even less intense physical activity, such as walking. Eating certain foods before exercise or exercising when the weather is hot, cold or humid also have been linked to anaphylaxis in some people. Talk with your health care provider about precautions to take when exercising.

>If you don’t know what triggers an allergy attack, certain tests can help identify the allergen. In some cases, the cause of anaphylaxis is not identified (idiopathic anaphylaxis).

Hope that helps.

Tl;dr: (as I understand it)— more or less, some people’s physiological response to infection or venom intake; for lack of a better explanation: “over reacting” from a viewing perspective of how one persons body reacts as opposed to another— while the body feels it’s necessary, it can kill you.

Im definitely not a doctor. I’d probably read the article to fill in any gaps, but I sort of paraphrased it in the tl;dr.

Anonymous 0 Comments

Your body is trying to kill the intruder *at all costs*

Allergic reactions are your body seeing a benign(non-harmful) thing come in and hitting the panic button so it sends up alarms and gets the troops (immune system) to come fight it. One of the ways your body fights things is by releasing all sorts of cells that cause swelling.

Anaphylactic shock happens when your body panics and instead hits the “Nuclear launch detected!” button and release *all* the troops to go fight *everything* and just creates a huge amount of swelling which ends up blocking airways.

Allergies are incorrect triggers of the defensive systems to start with. Extreme allergic reactions come about when your immune system enters a battle to the death with something it can’t kill but it is a battle to the death soooo

Anonymous 0 Comments

Biological machines are not perfect. People act like Nature’s playing a video game and making decisions based on what will work best. In reality nature is just rolling dice and giggling at the outcome, with very little thought involved.

Anaphylaxis is a kind of allergic reaction. We still don’t understand a lot about allergies, but we know they’re a situation where the immune system goes too far. Imagine a fire crew shows up to a burning building and finds the fire is in just one room. They proceed to put the fire out, then walk through every room, spraying every wall with their firehoses so thoroughly the drywall comes apart. By the time they leave they’ve done more damage to the structure than the fire they came to fight.

That’s kind of what happens when an allergic reaction starts causing anaphylaxis. We think allergens are stuff the body identifies as bad that the immune system should attack. Sometimes that alone is one of nature’s little mistakes.

Across humanity, the average response to one of those triggers is not life-threatening. You might get sneezy, or a runny nose. That’s meant to expel airborne things. That happens by making tissues in certain places swell or activating certain glands. That’s why you also might get hives, or a wound where stuff got in gets sore. It’s part of and side effects of how your immune system deals with stuff, kind of like how the firefighters still damage a lot of stuff even when they’re careful.

But in a few rare people where nature’s experimenting, the tissue swells A LOT or the glands go into hyperdrive because the immune system isn’t like “get this out” but “HOLY SMOKES WE HAVE TO ELIMINATE THIS”. This system is already insane, so it doesn’t much care if it’s swelling your throat so much it blocks your airways, and the brain’s not set up to handle this kind of malfunction.

That’s also why the medicines we have in things like Epi pens work so well. They’re chemicals that tells the immune system “CHILL THE HECK OUT YO” very aggressively. This isn’t great either, and it tends to take a pretty big toll on a person’s body. But it saves their life, so it’s worth it. There’s just not a great way to dose it out so their immune system chills “a little”.

We’re still learning a lot about how this all works. One of the ways COVID kills people is very similar and we don’t know an awful lot about that either: it seems adept at teaching our immune system to fight our own body. Worse, we’re starting to learn some diseases can “erase” the “memory” our immune system has (this was discovered as a property of measles, and we’re suspicious COVID can do it too.)

So think about this pretty hard when people say “let nature take its course”. Sometimes “nature’s course” is to program someone’s body to kill itself if they pet a cat. To me that’s a pretty darn good reason to rebel against nature’s course at just about any opportunity we have.

Anonymous 0 Comments

Anaphylaxis is really dangerous, and probably the most lethal part about it is the amount of narrowing of airways that makes it near impossible to breathe. Inflammation specifically is designed to open up your blood stream to allow things like white blood cells and other types of cells to flow through and repair whatever is causing the problem. There is an issue here, though, in that there are blood vessels in your throat too.

Sometimes your body gets a little too confused and thinks opening up your blood vessels is more important than breathing itself, among other important functions in the body. It will inflame basically every blood vessel so that tons of anti-virus anti-bacterial junk can flow like crazy. So it does this to your throat’s blood vessels as well. Your throat inflames and bloats up so much that you can’t breathe. Blood will flow quite well, though. So really, your body is not trying to “kill” anything bad by closing your airways, it is more of a reaction.

Anonymous 0 Comments

**Histamine** is a biochemical that has a significant role in both generalised and local immune responses. It is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues.

As others have noted, allergic reactions of the type leading to anaphylactic shock are an immune system response that is out of proportion to the threat posed by an allergen. This causes a systemic flood of histamine through the body, far beyond the site of the initial stimulation.

This opens capillaries to allow antibodies to reach the site of the allergen, causing flushing of the skin and swelling of mucus membranes, and often the skin as well. Swelling of mucus membranes of the throat, trachea and bronchi will restrict breathing. In addition, this opening of the capillaries and other histamine effect on the circulatory system has the effect of lowering blood pressure, causing the “shock” of anaphylactic shock. In combination with the restricted airway, the human body is suddenly and significantly stressed, and other physiological responses to stress also kick in.

Epinephrine (as delivered from an Epipen) is used to reverse some of the effects of histamine during anaphylaxis. It has an impact on smooth muscle in the blood vessels, reversing the dilation and increasing blood pressure. It also relaxes the smooth muscles in the airways and lungs, countering the effects of swelling and making breathing easier. It is also used in this way to relieve asthma.

Anonymous 0 Comments

Your body is trying to kill the allergen because it mistakenly recognizes it as a threat. Your body is trying to get rid of the thing at all costs, even if it kills you and swelling up is one of your body’s defenses. It’s basically like trying to kill a fly with a nuclear bomb instead of a fly swatter. Your immune system misjudges how much of a threat it is and takes extreme measures

Anonymous 0 Comments

Your body has cells blow up and release chemicals that cause inflammation to tell the rest of your immune system to fight something at that location. One of the effects of those inflammation causing chemicals is to make more of that same cell type likely to blow up and release more of the same chemicals. Anaphylaxis is when there’s a chain reaction of these cells and they basically all blow up, similar to lighting a firework that goes off too close to the whole box of fireworks and all of them go off.

As the fireworks are going off, everywhere starts swelling, including the throat, which makes it hard to breathe. The other problem with the swelling is that the liquid causing the swelling has to come from somewhere and it mostly comes out of your blood, so then there isn’t enough blood flowing around your body. Between the lack of blood, and the airway swelling, a severe allergic reaction can kill you without medicines that are designed to prevent, stop, or slow down all of the “explosions” going off in your body.

Anonymous 0 Comments

I hope it doesn’t hijack the OP’s question, but would a good analogy be that the body has a scorched Earth policy? It will win at all costs, even if it happens to damage the body it’s trying to defend?

Anonymous 0 Comments

There’s a general reaction of swelling up and expanding all the blood vessels locally when there’s a lot of germs in a particular part of your body, because that lets immune cells reach the area easier to fight the germs more efficiently. There’s no exception to that reaction in your lungs, because if there were a lot of germs in your lungs before modern medicine you were probably screwed anyway, so there was no benefit to evolving an exception.

Allergies are caused by your immune system misidentifying a harmless protein from something around you, like food or dust, as germs trying to kill you. The classic allergy test where they prick the skin of your back and you get welts in some of the spots works because the thing they prick you with has a foreign protein in it. When it gets that protein under the skin, your body misidentifies it as an infection and that spot swells up to help immune cells reach the infection.

So similarly anaphylactic shock happens when something you’re allergic to is present in your airway and lungs (it can get there through the air or through your bloodstream). Your body thinks you have a serious infection in your respiratory system, and reacts to that like a serious infection anywhere else — by swelling up to let the immune cells in. Your airway swelling up kills you without treatment, but lung infections as serious as the one your body mistakenly thinks you have would kill you without treatment anyway.