Reducing fever, good or bad

Lower

fever

,

good

or bad Fever If someone has a

fever

, it means that the body temperature is higher than normal. They have a fever. This video is about whether this is

good

or not. When someone has an infection, their body temperature rises. And this increase in body temperature makes the environment more hostile to the bacterial or viral invader. They do not like it when the temperature exceeds 37 degrees Celsius. Additionally, fever will increase the activity of your body's immune system. So what we see in this video is that fever is a natural adaptive response that helps us fight infections.

Well, let's get straight to the main point of this video if you don't have time to watch the whole thing. We have medicines called antipyretics (antipyretics). ). These are medications such as paracetamol and ibuprofen that reduce body temperature. These medicines to reduce fever. And very often, when these medications are administered, the effectiveness of the immune system is reduced. So the goal of this video is to allow us to be careful when administering antipyretic medications because we are going against the body's natural immune response. Well, what an infection is is the presence of virus particles in the body, in the tissues.

Or the presence of bacteria in the body's tissues, these little bacterial cells. If you compare the sizes, a virus is about this size (dot) and a bacteria is about this size. Viruses are much smaller than bacterial cells. So this drawing shows the scale. These are viruses. This is a bacteria. A viral or bacterial infection of this type is the presence of these things in the tissues of the body. They are both foreign objects. They are not part of you, they are not me (they are not part of yourself). Therefore, both will be recognized by your body's immune cells.

Your body's immune cells are these white blood cells here. There are different types of white blood cells. Here the body has different types of white blood cells. And all together they are called leukocytes. The body's white blood cells. These are immune cells, white blood cells. Not red blood cells, they carry oxygen. These are white blood cells that have an immune protective effect. And once these white blood cells, leukocytes, detect the presence of bacteria or foreign viral proteins. What they then do is release chemicals called pyrogens. Pyrogens. And pyrogens are an example of a cytokine. And a cytokine is a messenger between different cells.

And pyrogen means that these specific cytokines cause pyrexia. Pyrexia and fever are the same. They then cause pyrexia. How do they do that? What these pyrogens do is go to a part of the brain called the hypothalamus. The hypothalamus. Then they go to the part of the brain called the hypothalamus. And the hypothalamus is what we call a thermoregulator. That is, it regulates body temperature. It is the thermoregulatory part of the brain. And as for the pyrogens... And as soon as the hypothalamus notices that there are pyrogens present, what the hypothalamus does is increase the set temperature point.

At first that fixed point was 37 degrees Celsius, to check the body at 37 degrees Celsius, and that now it is rising to a feverish temperature. Let's say 39 degrees Celsius. And that means that the body is now trying to reach a temperature of 39 degrees Celsius and not 37 degrees Celsius. And to achieve this, the hypothalamus makes you feel cold and shivering. You put on blankets and sit near the heater and the chills cause your metabolism to produce heat. The blood vessels in the skin narrow to retain as much heat as possible. So that your body temperature rises to this new fever temperature.

And to achieve this, your body uses a lot of energy. This is an energy-intensive process. This is a very conscious process with different phases. We have the viruses, the bacteria and the white blood cells that produce pyrogens, they go to the hypothalamus where they attack these temperature regulating cells in the hypothalamus, which causes the set point to increase, which causes the body to increase its temperature. When the temperature is above this, we say that the person is febrile or has a fever. So what we see is that this is a very conscious process, it's not something that happens by accident.

This increase in body temperature to this feverish temperature is good whether we have a viral or bacterial infection. So let's look at the viral infection first, here you see a virus that has entered the body. These virus particles have entered the body because we have been exposed to an infection. So now we have virus particles in the body. Virus particles cannot reproduce themselves. Then they enter the cells of our body, so here you see one of our tissue cells with a nucleus in the middle. That is one of our tissue cells, and the virus particles enter this cell.

And in this cell they produce more and more virus particles. These new virus particles are released from the infected cell and then move to another nearby cell that is not yet infected with the virus. But then the virus particles enter the cell, and when they are in the cell, they multiply again. Virus particles will then be released and infect other cells, causing this "chain reaction" of infection. So this is what normally happens in a viral infection, remember that virus particles can only reproduce inside a living cell of the body because they are what we call 'obligate intracellular parasites'.

When cells get infected, what they do is: when they get infected. In the case of a virus, they release substances called interferons. Interferons are involved in the reproduction of a virus, so cells release interferons to other cells in the body that are not infected, so let's imagine that they are interferons and that the interferons fit into special receptors on the surface. of uninfected cells, if we look at this closely, if that were the surface of this uninfected cell, here there would be a receptor on the surface of the cell. A specific receptor for interferons that would bind with interferon. that has been released from the infected cell.

So it works as if the interferon is the key and the interferon receptor is the lock that the key fits into. When this happens, the receptor sends signals to the cell, allowing it to change. That will do two things: It will cause this cell to produce antivirus enzymes, which are enzymes that will act against the virus, around the cell and, of course, inside the possibly infected cell. It will also cause other substances to be produced within the cell to enable protein synthesis, so that the cell can perform protein synthesis. As a result, there will be less protein synthesis in the infected cell.

And that means that if this cell were infected by the virus, it would not be able to produce new virus particles, because normally the virus uses the cell's own genetic material to produce the proteins that form the next generation of the virus. are. Therefore, in a viral infection these interferons are essential and are more active at febrile temperatures. So when someone has a fever, it will enhance this interferon-based mechanism, giving it antiviral effects, so the body can better protect itself. But what really happens here, if you have an infected cell here, imagine, if this cell has virus particles and they multiply like this, the interferons will go to the surrounding cells, to the cells that are around it, and it makes the cells surrounding cells to produce antiviral enzymes and also eliminates the ability of these cells to produce new viral proteins, which means that when the virus is released from the cell, they will be attacked by antiviral viral enzymes, which is. very well, and even if they could get into one of the cells, the virus cannot multiply.

What that means is that this group of cells stops the virus, preventing it from spreading to other tissue cells in the body. In this way, a kind of wall is created around the infected cells, which prevents the virus from spreading throughout the body. This is how it works and also, when you have a viral infection, you have specialized blood cells called lymphocytes and these lymphocytes produce special antiviral proteins called antibodies. These antibodies will also attack the virus directly and kill the virus particles. They do this by binding to the virus particles, making it "inactive" and binding the virus particles to each other so they can be consumed by special large cells designed to eliminate the infection particles, called phagocytes. and all of these mechanisms work best at febrile temperatures.

So if we try to lower the body temperature from the outside, all these antivirus mechanisms that are working in the body, made possible by the fever, will still happen, but not as efficiently and quickly, which is why we see the fever trying to help the body to fight against virus particles, making interferons more active, making more active lymphocytes produce antibodies to fight the virus, which gives the body the opportunity to eliminate the infection and, in addition, the antibodies have an immunity more durable. against the virus. Elevated temperatures also help prevent bacterial infections, in addition to viral infections.

So the red things you see here are bacteria that have entered the body and, when left alone, double in number every half hour, or even faster. Then they see that there is an exponential growth in the number of bacteria. This can cause a potentially fatal bacterial infection. That is why we have to counteract these bacteria. This happens first with the body's cells called neutrophils. So here's a neutrophil, just a kind of white blood cell. This one here has several lobes in the nucleus of the cell. This cell looks special. This is a neutrophil, a special type of white blood cell.

The special thing about these cells is that they can move on their own, they can migrate. Therefore, this cell is mobile and can move towards the bacteria. Because what happens is that the cells of the bacterial infection release substances, since they do not belong to the body, they will release other substances. and in the vicinity of these bacteria there will be many foreign substances. Then they will slowly float away from the bacteria. These cells are collected by neutrophils, what the neutrophils do is that they 'smell' them, the neutrophil recognizes the foreign substances, and what the neutrophil, the white blood cell, then does is move towards the bacteria because the neutrophils move towards superior levels. concentrations of foreign substances from the bacteria and eventually reach the bacteria, and other cells will also do the same, those cells are called monocytes and they are also large.

The tissue also contains other large cells that also do this, they are called macrophages. Many different types of white blood cells will progress toward bacterial infection. When they get there, what they do is they reach a bacterial cell and then they don't stop moving, so at a certain point the white blood cells are right next to the bacterial cells, as you can see here what happens. , are these two ends of the white blood cells that surround the bacteria, so if we look at this a few seconds or minutes later, the bacteria will almost be inside the white blood cells.

As you can see here, they will soon be there and when these ends have joined together they will close, after which special organelles in the cells release digestive enzymes. They digest and kill bacteria, that's what happens. And all this white blood cell movement happens much faster at febrile temperatures. So when you have a fever, everything happens much faster. So what we see here is that when you have a fever, the body fights viral and bacterial infections better. Therefore, the body can fight bacterial infections better. So viral infections die faster and bacterial infections die faster. allowing us to heal from the infection faster.

But if we artificially lower the body temperature, what happens is that the antiviral mechanisms become slower and the antibacterial infection mechanisms become slower. This allows bacteria and viruses to multiply faster in the body. Therefore, we will have a greater number of bacterial infections. And virus infections. More virus particles, more infectious bacteria, making us feel sicker, that's what happens. So if we artificially lower the body temperature the processes slow down, but if we simply leave the temperature in an adult, for example if my temperature is 39° C and I simply let it pass, I only said adults, I will talk about Children speak again, so if my temperature is 39° it's not really going to hurt me, but I know it will stop the infection faster.

So if I artificially lower my body temperature with, for example, ibuprofen, acetaminophen or paracetemol (acetaminophen and paracetemol are the same thing), what I do is counteract the infection-fighting process, ensure that the infection lasts longer and increase the risk of complications with infection. So we see that fever is a natural protective mechanism and often only needs to be left alone in adultsto prevent infection. to be able to combat the disease and have fewer complications and a shorter duration of the disease.