Articles, Blog

Pneumonia – causes, symptoms, diagnosis, treatment, pathology

August 14, 2019

Pneumonia is an infection in the lung tissue
caused by microbes, and the result is inflammation. The inflammation brings water into the lung
tissue, and that extra water can make it harder to breathe. During inhalation, air reaches your lungs
by traveling down your trachea, then it continues through the bronchi and the bronchioles and
ends up in the alveoli. The alveoli are tiny air sacs that look like
tiny clumps of grapes, that are wrapped up in a net of capillaries. This is where the majority of gas exchange
happens in the lungs. Oxygen leaves the air in the alveoli and crosses
into the bloodstream while carbon dioxide leaves the bloodstream and is then exhaled
out of the body. Now, now in addition to air, you’re constantly
breathing in other stuff, like microbes. But we’re usually good at protecting ourselves. For example, we have mechanical techniques
like coughing, a mucociliary escalator that lines the entire airway and moves out larger
bacteria, and macrophages that are nestled deep inside the alveoli and ready to destroy
anything that lands there. But sometimes, a particularly nasty microbe
might succeed in colonizing the bronchioles or alveoli, and when that happens – Congratulations! You’ve got pneumonia. Those microbes typically multiply and cross
over from the airways into the lung tissue, creating an inflammatory response. The tissue quickly fills with white blood
cells as well as proteins, fluid, and even red blood cells if a nearby capillary gets
damaged in the process. Now, there are lots of different pneumonia-causing
microbes. Usually it’s caused by viruses and bacteria,
but it can also be caused by fungi and a special class of bacteria called mycobacteria. In adults, the most common viral cause of
pneumonia is influenza, sometimes just called the flu. In adults, bacterial causes include streptococcus
pneumoniae, haemophilus influenzae, and staphylococcus aureus. There are also more unusual bacteria like
mycoplasma pneumoniae, chlamydophila pneumoniae, and legionella pneumophila, which don’t
have a cell wall and are well known for causing an “atypical or walking pneumonia” because
they often cause vague symptoms like fatigue. In individuals with a normal immune system,
fungi are a rare cause of pneumonia and often it’s regional – for example, there’s Coccidioidomycosis
in California and the Southwest – which you can remember because there’s a “C” in
both cocci and california, Histoplasmosis in the Ohio and mississippi river valleys
– “H” in Histo and in O”H”io, and Blastomycosis which are broad based budding
yeast which are in the east – you can remember that with the “east” in yeast. And the broad based budding refers to the
fact that under a microscope, when the fungi bud off of each other there is a broad versus
a narrow based. To round out the fungal causes in the US,
there’s Cryptococcus which is “cryptic” because geographically it can pop up really
anywhere. Now, one special fungal culprit is pneumocystis
jiroveci which is a risk for immunocompromised individuals. Finally, there’s mycobacteria which are
slow-growing like fungi, hence the “myco” in their name even though they’re still
bacteria. The most well known one is mycobacterium tuberculosis,
also just called TB. Pneumonia can also be categorized by how it’s
acquired. The most common, is community acquired pneumonia,
and it’s called that when a person gets sick outside of a hospital or healthcare setting. Next is hospital-acquired pneumonia or nosocomial
pneumonia, which is when a person gets pneumonia when they are already hospitalized for something
else. This type tends to be more serious because
sick patients often have a weakened immune systems and the microbes in hospitals are
often resistant to the common antibiotics. That’s because hospitals bring together
the bacteria that are often the most virulent – think great offense – as well as the most
resistant – think great defence. These bacteria are able to swap some of the
antibiotic resistance genes with one another. A well known example is Methicillin-resistant
staphylococcus aureus, or MRSA. Non resistant staph aureus can cause pneumonia
and other infections, but it can also be killed by common antibiotics like ampicillin. MRSA on the other hand is resistant to many
antibiotics and is therefore harder to treat. Another category of pneumonia is ventilator
associated pneumonia, which is a subset of the hospital-acquired pneumonia, but it specifically
develops when ill individuals are connected to a ventilator. Oftentimes, there’s a biofilm – which is
a mix of bacteria and sugars and proteins that can coat a surface – that forms on the
endotracheal tube. Individuals on a ventilator can’t cough
and are often quite sick already, so over time microbes can move from the tube directly
into the lung and cause a pneumonia. Now in addition to inhaling microbes there
are other ways to develop pneumonia. Think about this: you’re eating some french
fries, and instead of swallowing one, you accidentally breath it in. Informally we call that going down the wrong
pipe, but we could also say that you aspirated that french fry. Normally, you’d automatically gag and start
coughing, and work that french fry out of your lungs. These gag reflexes can be compromised, however,
by drug and alcohol abuse, brain injuries, or swallowing issues. So in these cases the french fry might stick
around in your lower airways. Now, of course, that french fry isn’t sterile,
there might be some microbes stuck to it. If those microbes infect the lungs and you
get pneumonia, we would call that this french fry pneumonia—just kidding—we call it
aspiration pneumonia. Aspiration pneumonia can also happen with
drinks, or even gastric contents, like after a bout of vomiting. Aspirated gastric contents can be particularly
nasty because the stomach acid can cause a chemical irritation in addition to the possible
infection. Another way we can characterize pneumonia
is by where the infection is. In bronchopneumonia, the infection can be
throughout the lungs involving the bronchioles as well as the alveoli. In atypical or interstitial pneumonia, the
infection is mainly just outside the alveoli in the interstitium. And in a lobar pneumonia, the infection causes
complete consolidation of a whole lobe of the lung, meaning that the entire region is
filled with fluid. The vast majority of these are caused by the
streptococcus pneumoniae. Usually, lobar pneumonia happens in stages. The first stage is congestion, and it happens
between 1 and 2 days. This is where the blood vessels and alveoli
start filling with excess fluid. The next stage is red hepatization, and it
happens between days 3 and 4. This is where exudate, which contains red
blood cells, neutrophils, and fibrin starts filling the airspaces and makes them more
solid. The name hepatization refers to the lungs
taking on a liver-like appears from the reddish brown color of the exudate. The third stage is gray hepatization, which
happens around days 5 to 7. In this stage the lungs are still firm but
the color has changed because the red blood cells in the exudate are starting to break
down. The last stage is called resolution, and this
happens around day 8 and can continue for 3 weeks. In this stage the exudate gets digested by
enzymes, ingested by macrophages, or coughed up. Pneumonia most often causes dyspnea, or shortness
of breath, chest pain, and a productive cough, meaning that pus or bloody sputum might come
up. Often there are also systemic symptom like
fatigue and fever. Diagnosis of pneumonia is usually made in
a person who’s working hard to breath or breathing quickly. A chest xray of bronchopneumonia typically
shows patchy areas that are spread out throughout the lung, in atypical or interstitial pneumonia,
the pattern is also often spread throughout the lungs but is often concentrated in the
perihilar region and looks reticular, meaning there will be more line shaped opacities visible
in a chest x-ray. In a lobar pneumonia, fluid is localized to
a single lobe or set of lobes. Another way to detect a lobar pneumonia, though,
is to look for dullness to percussion which suggests that there’s a lung consolidation. There’s also tactile vocal fremitus, which
is when you can feel more vibrations from a person’s chest or back after they repeat
certain phrases. This is because sound travels better through
the fluid-filled consolidated tissue than air-filled healthy tissue. Late inspiratory crackles may also be heard,
along with bronchial breath sounds, bronchophony and egophony. The treatment of pneumonia depends on the
type and severity of pneumonia. Since bacteria are the most likely cause antibiotics
are often prescribed. In addition, cough suppressants and pain medications
are often used to help with symptoms. Alright … as a quick recap. Pneumonia is an infection of the lungs that
results in air sacs being filled with fluid. The disease can be classified by being either
community-acquired, hospital acquired with some of those being ventilator associated
pneumonias, or aspiration pneumonias. Pneumonia can also be characterized by where
the infection is in the lungs. Bronchopneumonia is spread throughout the
lungs, atypical or interstitial pneumonia happens interstitium around the alveoli, and
lobar pneumonia usually infects an entire lobe of the lung.


  • Reply Rasheed Sk Sk October 14, 2018 at 12:16 pm

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  • Reply HadeelAsb October 15, 2018 at 3:36 pm

    you're a life saver thank you๐Ÿ˜ญ

  • Reply Collin McLaughlin October 15, 2018 at 11:13 pm

    I cant breathe I don't have time for a McDonald's ad

  • Reply meme fabulous October 19, 2018 at 8:43 pm

    Ha… I'mprettysureIhavepneumoniakillme

  • Reply Elif Khan October 21, 2018 at 3:41 pm

    Iโ€™m loving these videos ๐Ÿ˜ญ๐Ÿ˜ญ๐Ÿ˜ญ๐Ÿ˜

  • Reply Ahmed Jawabra Ahmed Jawabra October 22, 2018 at 7:34 am

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  • Reply Romana Ahmad Mir October 26, 2018 at 7:32 pm

    You guys are the best. Big love!

  • Reply shkar abdulla October 28, 2018 at 1:59 pm

    man u save my life tomorrow i have exam , well done

  • Reply Lakshman Hithu October 29, 2018 at 6:13 am

    Thank you

  • Reply Misbah Wani October 30, 2018 at 8:31 am


  • Reply minibunny October 31, 2018 at 11:49 am

    Can you site this pls

  • Reply garrisp November 9, 2018 at 1:44 pm

    Hospital pneumonia was also known as โ€œan old mans best friendโ€ because of its euthanasia affect.

  • Reply Dr.Mohammad Rafi safi November 9, 2018 at 9:27 pm

    Hi, I love your lecture.
    Specially that French fry

  • Reply Mark Talbert November 10, 2018 at 12:52 pm

    Pneumonia isnt a joke. my mom passed away from it. cunt

  • Reply Jack Salvatierra November 12, 2018 at 2:59 pm

    Hi, this video is the best on pneumonia!

  • Reply JOLLY SPIDEY November 13, 2018 at 10:13 am

    Stan Lee died because of this..

  • Reply Lola A. November 14, 2018 at 8:54 am

    Evan, my boy, your kindness made my day! You seem like an amazing person!

  • Reply Bintang Ekananda November 15, 2018 at 10:41 am

    Composer Franz Liszt dead because this virus!

  • Reply mah noor November 17, 2018 at 10:17 am

    French fry pneumonia๐Ÿ˜œ๐Ÿ˜œ๐Ÿ˜œ

  • Reply Jen Fabula November 17, 2018 at 7:13 pm

    Thank you guys!

  • Reply npgSymboL November 18, 2018 at 5:19 am

    Is the congratulations really necessary? Some people find your video when they nearly loose someone..

  • Reply ahmed azeez November 18, 2018 at 11:54 am

    Colonization isn't equal to infection. eg, most of bronchiectasis patients colonized with pseudomonas, but with out clinical and radiological changes you can't say its pneumonia.

  • Reply Raynaldi Pangestu November 19, 2018 at 12:28 am

    eaa bisa ngelawak juga yak osmosis

  • Reply judy hops November 19, 2018 at 8:07 pm

    thank you soooooo much

  • Reply Jerry Christopher November 21, 2018 at 11:18 pm


  • Reply catwesage November 27, 2018 at 3:31 am

    One minor correction: Legionella DOES have a cell wall as it is a gram – microbe.

  • Reply Eva Kristiansen November 28, 2018 at 10:11 am

    The sound effects are way too much! plz don't make a habit of this :i

  • Reply Simmi Kaur November 28, 2018 at 11:07 am

    Thanks for given me information about pneumonia

  • Reply Mahfuza Mouri December 1, 2018 at 3:00 pm

    Thanks a million for this .

  • Reply Nagma Nagma December 3, 2018 at 2:36 am

    Very good bro

  • Reply Xahvia Braun December 9, 2018 at 5:44 am

    Well done! The best video on the subject. Lots of important facts, clearly explained without superfluous details. To everyone on the team, thank you for sharing! Blessings to all!

  • Reply Bayan Alyahyaei December 9, 2018 at 6:13 pm

    I like French fry pneumonia ๐Ÿ˜‚๐Ÿ’™

  • Reply MahmouD ebn.jordan December 15, 2018 at 5:22 pm

    why you donโ€™t talk about managment !?

  • Reply dam is hype dam is chill December 16, 2018 at 10:26 am

    congratulations you guys got pneumonia ๐Ÿ˜‚

  • Reply Joe Shasho December 17, 2018 at 8:32 pm

    love these!! God bless you guys.

  • Reply *โ€ข.ยธโ™ก Shuumin Drawz โ™กยธ.โ€ข*/Elizabeth December 18, 2018 at 5:52 pm

    I had that ;-;

  • Reply Somya Tayal December 19, 2018 at 4:52 am

    u guys r amazing .. ur videos r really informative n up to d point. โ™ฅ awesome work

  • Reply Avneet kaur December 23, 2018 at 3:48 am

    just love your videos ๐Ÿ˜‡ really very easy to understand ๐Ÿ‘Œ…keep doing the good Work…๐Ÿ‘

  • Reply rukhsar fatima December 23, 2018 at 1:56 pm

    French fry pneumonia๐Ÿ˜‚

  • Reply Matika Shepherd December 27, 2018 at 4:46 pm


  • Reply Aryanna December 30, 2018 at 9:06 am

    lmao @ french fry pneumonia

  • Reply Gt I January 3, 2019 at 12:01 am


  • Reply MAHI SINGH January 7, 2019 at 9:28 am

    love live

  • Reply Maryam Nadeem January 11, 2019 at 5:06 am

    This is my all time favourite channel to learn and prepare myself for exams. Thank you so much!

  • Reply ุฒุงุฏ ุงู„ู…ุณู„ู… January 12, 2019 at 1:46 pm


  • Reply Aiko Fukuhara January 18, 2019 at 6:21 am

    I had pneumonia as a kid, but I never really knew what it was so thank you for explain it.

  • Reply the peanut butter January 23, 2019 at 1:15 pm


  • Reply JENNIFER BACO January 23, 2019 at 9:24 pm

    I enjoyed it with french fries pneumonia hahha ๐Ÿ˜‚

  • Reply Ethan at gacha February 1, 2019 at 1:40 am

    Thank you know I know why i have pneumonia Iโ€™m going to the hospital now

  • Reply lakshmi narayana February 5, 2019 at 4:59 am

    Hi Guys i need to information on best lungs disease treatment hospitals in india

  • Reply Ajmeer Krishna Aju February 8, 2019 at 4:10 pm

    The video is simply awesome… I'm having my test on Tuesday… I hope this helps…. ๐Ÿ˜๐Ÿ˜๐Ÿ˜

  • Reply Irshad Ismail February 10, 2019 at 3:13 pm

    kidu pneumonia

  • Reply Peter Reynold Robinson Junior February 10, 2019 at 7:47 pm

    You guys help me soo much, that I am trying to pay back the favor. I am trying to correct the subtitles of the videos as I am watching them, so I can share with my classmates here, as many of them do not know English. Bye!

  • Reply Ceecee Nj February 11, 2019 at 7:12 pm


  • Reply ไฝ•็ฆน้พ February 17, 2019 at 8:41 pm

    Is there a film of acute respiratory distress?

  • Reply Victor Von Doom February 18, 2019 at 11:42 am

    For anyone doing a research like me….

    What is Pneumonia?
    Ans: Difficulty to breathe because of microbes

    Causes: Influenza or sometimes some Fungi

    Symptoms: Extreme Difficulty to breathe, Fatigue

    Treatment: Medication(note: though sometimes the virus is immune to antibiotics)

    Credits to this video

    This was specifically made for a graphic organizer or a chart of leading mortality rates btw

  • Reply army bts February 24, 2019 at 5:08 am

    ๐Ÿ˜๐Ÿ˜thanks for the is very helpful

  • Reply Ogrillion February 26, 2019 at 12:57 pm

    Just wanted to say thank you for making all these videos. I am in nursing school and find all of your videos very helpful.

  • Reply abhishek gupta March 3, 2019 at 1:23 pm

    Plz add complications,dd's and treatment then u will become the best channel

  • Reply happy earth happy life March 4, 2019 at 2:21 pm

    Your videos r so helpful please add some more details

  • Reply Zulaika Harissya March 11, 2019 at 3:09 pm

    Can you make video about esophagus cancer? I need it

  • Reply Sarah Gh March 25, 2019 at 8:05 pm

    ุดูƒุฑุง ู„ูƒู…

  • Reply ashley millan March 30, 2019 at 10:02 pm


  • Reply Solomon Offor April 1, 2019 at 10:40 am

    Fungi is pronounced as fun-gai not fun-jai 1:41

  • Reply Aa perm April 5, 2019 at 9:29 am


  • Reply treasure edet April 11, 2019 at 9:55 am

    I really loved this video it was of great help. Please could you do a video on bronchiectasis

  • Reply Sai Vardhan April 14, 2019 at 7:48 am

    Can pnuemonia cause vomiting diarrhea…and how ??

  • Reply Hafizah Hoshni April 14, 2019 at 3:58 pm

    I almost believe when you said French Fry Pneumonia 5:50 haha ๐Ÿ˜‚๐Ÿ˜‚ 14/4/2019

  • Reply kochi tokyo April 15, 2019 at 2:38 pm


    Sorry for my bad English, is pneumonia curable? My 1st newborn son, who born today april15,2019, is diagnosed with pneumonia, my son is being treated but i just want to know if its curable? is it possible that we dont have to deal with pneumonia as he grow up?

  • Reply RoHaN April 22, 2019 at 11:53 pm

    Thank you osmosis for amazing content on youtube as well as on application ……it helps alot for quick recap or revesion….love you osmosis

  • Reply Mufidatul Arun April 24, 2019 at 7:24 am

    thank you osmosis for making this video. its help me a lot ๐Ÿ™‚

  • Reply aburida karim April 28, 2019 at 10:32 am

    Please Make a video for Typhoid.

  • Reply leo kwong April 29, 2019 at 10:25 am

    Wait……. is rosesaila died because of this

  • Reply cringey gamer girl April 30, 2019 at 11:21 am

    I had walking pneumonia it wasn't treated for a month and i was still forced to go to school, after awhile i couldn't walk anymore and i have asthma so breathing was harder than it usually would be i was sick for another month and that's all i remember

  • Reply Sarah Goodman May 3, 2019 at 3:46 am

    Death by french fry…..First world problems๐Ÿ˜‚๐Ÿ‘

  • Reply elsy loid77 May 8, 2019 at 12:27 pm

    Thank u sir

  • Reply Mauro Ceccobelli May 10, 2019 at 1:40 pm

    My Name is Monia. Wtf

  • Reply Brad Gates May 10, 2019 at 10:31 pm

    whenย  was just seven months old I had MRSA. for two monthsI nearly died

  • Reply vortexx killaxx May 11, 2019 at 7:18 am

    nfortunate but i have had this twice (than and now present again). What are signs to look out for?
    well during the onset i noticed Sinus aches and mild body aches, these would come and go, eventually i got the ''Flu'' but this wasn't any Flu, it included severe coughs, body chills, yellowish skin, and i had trouble breathing, i was taken to hospital and got diagnosed as having 'Bacterial Pneumonia' in its severe-life threatening form and hypoexemia, i was in hospital for 5 days, even after discharge it took an extra week to get back to my activities. Worst illness i have ever had. This was in 02/2019.

    05/2019: Last week i noticed less severe but similar symptoms , it lead to coughing and body aches, i was given antibiotics but got worse so my GP gave me a stronger form, i was than Diagnosed with a 2nd bout of 'Bacterial Pneumonia'' but this time mild, with a non specified RTI, he gave me Nurofren plus and Doxicllyn, i am still sick now but feel better.

    Pneumonia is serious, if you notice Jaundice, trouble breathing, and extreme sweating while sitting down with body aches, it is a chance you have Pneumonia or Hypoexemia which need to be treated.

  • Reply Riya Kaf May 14, 2019 at 8:41 pm

    Thank You so much for your efforts ๐Ÿ˜Š

  • Reply G.R. Bryant May 16, 2019 at 5:50 pm

    His pronunciations are horrible, but the information is very useful and understandable.

  • Reply Mackson Juleseus May 17, 2019 at 1:22 am

    scary stuff

  • Reply ุงู„ูŠู…ู†_ ุงู„ุณุนูŠุฏ May 18, 2019 at 9:46 pm

    ุงุชู…ู†ู‰ ุงู† ุชูƒูˆูˆู† ุงู„ุชุฑุฌู…ุฉ ุถู…ู† ุดุฑุงุฆุญ ุงู„ูุฏูŠูˆ ุฏูˆู† ุชุฑุฌู…ุฉ ุฌูˆุฌู„ ุŒ ูˆุดุงูƒุฑูŠู† ุฌู‡ูˆุฏูƒ ุงู„ู‚ูŠู…ุฉ ๐Ÿ˜š

  • Reply Jennifer Spence May 20, 2019 at 6:00 am

    How long doe pneumonia last on surfaces ie a person coughs at the table, floor, couch, throws up a little with a cough fit onto the floor

  • Reply Dayapreet singh Sodhi May 22, 2019 at 1:45 pm

    Hey Evan , thanks for such a nice video , instead of reading textbooks for revision i watch your videos, great content buddy.

  • Reply JBN Healthy Life June 5, 2019 at 2:15 am

    Thank you so much

  • Reply udon mask June 6, 2019 at 12:38 pm

    I just got it help

  • Reply Revathi Puppy June 8, 2019 at 7:57 am

    Your voice is so nice …

  • Reply Revathi Puppy June 8, 2019 at 7:59 am

    I love your voice and way of your teaching style…. ur awsm…I fell into love with you ….. can you marry me ??

  • Reply Fahad Mumtaz July 1, 2019 at 7:19 am

    best video indeed .now i will stop eating french fries :p

  • Reply Amber Blyledge July 2, 2019 at 6:30 am

    But why are the lung lobes not even? BIOLOGY! WHAT THE HELL!

  • Reply Ems Fallout July 3, 2019 at 9:14 pm

    Does anyone know a program to make vids like this?

  • Reply TAARA the great NCTzen July 8, 2019 at 5:55 am

    I literally laughed my lung out at …FRENCH FRY PNEUMONIA ….nah its aspiration pneumonia๐Ÿ˜‚๐Ÿ˜‚๐Ÿ˜‚๐Ÿ˜‚๐Ÿ˜‚๐Ÿ˜‚๐Ÿ˜‚๐Ÿ˜‚๐Ÿ˜‚

  • Reply Rahul Gupta July 14, 2019 at 2:37 pm

    So nice video sir…….

  • Reply tractor July 15, 2019 at 2:38 am

    See how stupid are medical drs ! This kid is listing lot of nonsense , and nothing how to stop it. Medical crap doesn't help you.
    I know how to stay away from every microbe , never sick in my 70 years on this green earth.
    This vidio sucks , a medical crap !

  • Reply Lara O'neal July 18, 2019 at 6:47 pm

    Iโ€™ve read That we should get a liver enzyme blood test to see how our immune system is?

  • Reply Marielle Cabie July 28, 2019 at 8:23 am

    I almost took note of the french fry pneumonia๐Ÿ˜‚

  • Reply Princess Consuela banana hammock July 31, 2019 at 5:07 am

    I love this guy's sense of humour.he always makes a jokein his videos

  • Reply Tony Khabbaz July 31, 2019 at 4:04 pm

    damn it bro you are funny ๐Ÿ˜€

  • Reply rosna varughese August 5, 2019 at 12:16 pm

    The best team of teachers! Thanks a lot osmosis… Please continue with this… Helping me a lot to learn medicine…..๐Ÿ˜

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