 Hey everybody, Dr. O here. In this video, I'm just going to introduce the three different types of immune disorders. So we'll cover the immune system in great detail. We'll cover each of these immune disorders in more detail, but I just want to talk about them and kind of compare and contrast them here in this video quickly. So we're going to talk about the hypersensitivities, the immunodeficiencies, and autoimmunity quickly. All right, so we're going to start here with hypersensitivity. This is when your immune system overreacts or over responds when it's exposed to something. So your immune system should recognize antigens and should recognize some of them as foreign and should attack them. But if it's an overreaction and the response is way too large, that would be a hypersensitivity. So you want a sensitive immune system, you just don't want a hypersensitive immune system. So think about like the real common food allergies you're seeing nowadays. If someone has a peanut or a tree nut or a sip of milk or something, they shouldn't die from anaphylactic shock. The response should not be that big. Over here you see, you know, think about bee stings and being allergic to bee stings and an epi-pen. So the reason you see that is because when you have this massive immune response, you can go into what's called anaphylactic shock. So your immune system will cause, the chemical messenger is released by your immune system, will cause your airways to constrict, which means you can't move enough oxygen and get rid of enough CO2. And then it'll cause your blood vessels to dilate. And the problem with that is we don't have enough blood for all of our blood vessels to be dilated. That's why after a big meal, you feel kind of lethargic because the blood has moved from your muscles to your GI tract or when you're exercising, more blood's going to flow to your skin and your heart and your muscles, but that's because less is flowing to your kidneys and your gut. So, so your blood vessels all pop open, your airways constrict and that can certainly be fatal. So an api-pen uses epinephrine or adrenaline to counteract that because adrenaline will cause your airways to dilate and cause many of your blood vessels to constrict. So that's why this epi-pen can be a life-saving tool. All right, so that's a couple of examples of hypersensitivities when your immune system overreacts when it's exposed to an antigen, a cell surface marker. Next here we have immunodeficiencies. So on one end, we have an overreactive immune system, too powerful. On the other end of the spectrum, we have an immune system that's too weak. So it'd be immunodeficiencies. So they can be either primary or acquired. So primary, the example I think of and think of, and this here would be the bubble boy or the boy in the plastic bubble. There was actually a movie John Travolta made when I was a kid where he played this boy. So usually he would have been kind of sealed off in a room. This was a special suit that I believe NASA developed for him so he'd go out. But he had SCID, severe combined immune deficiency, so he just, he didn't have an immune system. All right, so that would be a primary immunodeficiency, but there also are acquired immunodeficiencies, and you've definitely heard of one, AIDS, the acquired immunodeficiency syndrome, and that's caused by the HIV virus. So a hypersensitivity is an overreactive immune system, immunodeficiency underactive or not functional at all. Then lastly is autoimmunity. So the immune system is not too strong or too weak. The immune system has lost its tolerance and tolerance would be the key word here. Your immune system should attack foreign invaders. It should attack pathogens. It should even attack organs or blood that's given to us if they're not a close enough match. But your immune system should know to leave your own tissues alone. So I have autoimmune diseases. I know way more about them than I like. We have a family history of them as well. So it isn't a strong or weak immune system. It's one that recognizes normal tissue as abnormal and attacks it and destroys it, which is what it should do. So the reason I chose this picture, this would be the hands of someone with rheumatoid arthritis. So rheumatoid arthritis, your immune system will attack and destroy your joints, thinking it's a foreign invader. My grandmother had rheumatoid arthritis. She was disabled for 20 years with that and her hands did look like this. I have psoriasis, other autoimmune diseases. You have Celiac disease, which is an autoimmune response to consuming gluten or more specifically the Gleed and proteins that are in gluten. Type 1 diabetes would be an autoimmune disease. We already mentioned rheumatoid arthritis, psoriasis, Graves disease. My mother had that. It's an autoimmune hyperthyroidism. So my mom's immune system would actually trigger the production of too much thyroid hormone. So they treated her when she was young by using radioactive iodine to destroy the thyroid gland. So there's about 80 different autoimmune diseases and that's where a normal or what should be a normal immune system recognizes normal tissue as abnormal. So the treatment for many autoimmune diseases is to suppress the immune system. But it's not that it's a too powerful of an immune response, it's just the wrong target. So you turn down the whole immune system. Okay. Just to review. Hypersensitivities, overreactive, too powerful immune response. Immunodeficiencies and underactive immune system not responding appropriately, not responding enough. And then autoimmunity keyword there is tolerance. Your immune system is attacking the wrong targets. Okay. I hope this helps. Have a wonderful day. Be blessed.