It's usually not a good idea to self-diagnose, especially via the Internet, but occasionally people get it right. And although doctors never encourage this, successful patients do impress them from time to time. Also, WebMD is terrifying.

Impulse_you_html asked, Doctors of Reddit, what's the weirdest case of someone self-diagnosing, and it being correct?

Submissions have been edited for clarity, context, and profanity.

I worked with an interventional radiologist/venous disease specialist and we had a self-referred patient who came to see us. She started off with "well, I've done lots of research on the internet" which is ALMOST ALWAYS A BAD START. However, this lady was a competitive cyclist and complained of unilateral leg weakness during her rides. She was otherwise very healthy. She had cycled miles and miles every day for many years. Suddenly she could barely finish a 5-mile ride. She had found online the diagnosis of external iliac artery endofibrosis which is very very rare, but more common in lifelong cyclists because they are bending over at such an angle for such long periods of times they are compressing their external iliac artery causing scar tissue to build up and limit blood flow. She asked my doctor to order her a CT scan because her other doctors would not (she was basically just complaining of being tired). But since we worked next door to a CT scanner we said SURE! Turns out she was right! She was then referred on to a vascular surgeon and I assume made a wonderful recovery. One of our shorter consults actually since it was so easy to rule in/out and she presented well researched, compelling evidence.

My attending had a patient with diarrhea and although he looked and insisted that he felt fine, his wife was insisting something was very wrong and she pleaded with us to do some blood work. So we did, not thinking we were going to find anything. Turns out the guy was in SEVERE kidney failure due to his dehydration from diarrhea (youngish healthy guy by the way). We would have never run that test and sent the guy to the ER if his wife didn't suspect that something terrible was wrong.

Not sure if this counts... when I was 25-28, my family and I were planning on going on a snow vacation in then still Czechoslovakia (before it split up) and woke up with a "weird" feeling in my stomach, no pain, just something being off. Went to my doctor, he felt around a bit, found nothing, and wanted to send me home. I refused and got a referral to the hospital (this was still all only because of my gut feeling) had bloodwork done, had an echo. All tests came back negative, the surgeon eventually came by, and we had a chat. Based on my words alone (not the results) he scheduled me for a laparoscopy to remove my appendix, stating "it will have to come out at one point, might as well do it early"

I went under, and woke up with a 15cm new scar on my belly, turns out my appendix was heavily inflamed and about to burst when they went in. Because I had no pain from it, I would likely only have found out my appendix burst on top of a snowy mountain, nowhere near any doctors, when my stomach would have gone septic, so good chance of dying.

The surgeon couldn't stop talking about how I probably saved my own life by being so adamant something was wrong.

Medical student here, I was the patient and I diagnosed myself.

I had this gnawing, dull pain on the ball of my foot for almost 6 months but during my surgery rotation, it got progressively worse since I was standing for most of the day. I couldn't even walk barefoot anymore (had to wear padded flip-flops at home or custom orthotics insoles outside). My foot would hurt at the end of my runs (surprisingly, not during my runs), when stretching my foot, and when pushing on the ball of my foot.

I told my primary doctor that I thought I had a sesamoid fracture because of my symptoms, risk factors, and duration of the pain. She didn't think so and told me to do RICE (rest, ice, compression, elevate) even though this had been going on for months. I said okay but also asked for a sports medicine referral just in case I couldn't find time to come back to follow up with her if RICE didn't work.

The sports med Dr. took x-rays of both feet, saw that one of the sesamoid bones had completely fractured into two, now VERY separate pieces. In a walking boot now and they're thinking of surgery if the pain doesn't get better!

Not a doctor, but a friend showed up to my dorm room and asked to borrow some anti-itch cream for what he said was a spider bite.

I told him that it was definitely not a spider bite and he should go to the doctor. He laughed and refused. I told him it might be MRSA and he should get it checked out. he kind of rolled his eyes but agreed to let someone look at it.

It was MRSA.

I told my doctor that I thought that I had a sinus infection. He commented that he didn't approve of people diagnosing themselves and asked me why I thought this.

My answer was "I can feel my teeth when I walk." He then laughed, confirmed the diagnosis through the exam, and prescribed antibiotics.

Medical student, here.

Had a patient in her 20's who felt a lump in her breast that she was concerned about. She had googled it and figured it was a benign fibroadenoma since it grew cyclically with her menstrual cycle but still wanted to check it out just to be safe.

She turned out to be right but she was wise to get it checked out, just in case she wasn't.

Finally something I can answer! I had, for my entire life since adolescence, a lymph node at the top of my tailbone area that would sometimes become swollen and painful and would have trouble sitting down. It would persist for a two to three days and then go back to normal.

I looked it up when I was a freshman in college and came across the term Pilonidal Dimple, which is a genetic abnormality present at birth, that along with my symptoms of being prone to infection, causes extra hair to grow out of it, which was also a problem I had. I was absolutely convinced.

I talked to my Mom, a nurse, about it, and then my GP who I had been with my entire life, and they didn't think that's what it was, mainly because it's a condition diagnosed at birth.

Fast forward to my sophomore year, the lymph node became swollen and the most painful it had ever been. I couldn't sleep. I went to the ER, because it was 4 in the morning, and told them I think this is the condition I have and the pain it's currently causing.

They take me back, the doctor comes in, confirms it, drains the infection, excises the node.

6 years later, have never had another problem with the lymph node pain. But I do still have a problem with hair growing out of it.

Recently had surgery. Went for a follow up a week later and the doc says everything is fine. Wife says "that looks infected". Doc blows her off and says it's supposed to look like that. 2 days later I'm lying in a hospital bed with doctors debating to amputate my finger and possibly my hand. My finger was severely infected. 7 days in the hospital, lots of antibiotics later was released.

Had arthroscopic knee surgery on a Wednesday morning. Felt great Thursday. Woke up Friday and had a little tightness in my chest but attributed it to having been intubated. Woke up Saturday and felt like an elephant was sitting on my chest. Walking 30 feet to my bathroom winded me as if I'd run a mile.

I called the on-call surgeon and explained my symptoms. He brushed me off and said I shouldn't worry given my age and overall health (I was about 37 or 38). I hung up and immediately called my mom to come drive me to the hospital. I knew something was seriously wrong.

They immediately did blood work and a chest CT. Within 20 minutes of getting to the ER they diagnosed me with multiple bilateral pulmonary embolisms. Blood clots in both lungs. I could have died at a moments notice.

Wound up in the hospital for a week on a heparin drip and on Coumadin for 6 months after.

A month ago I was being treated for pneumonia for pain under my ribcage with coughing. After that didn't work they were just going to write it off as muscle pain until I suggested it was my gallbladder. There were no stones in the ultrasound but I fought for a function test and it was only functioning at %14. Got it removed 3 days later.

This boggles my mind. My husband had severe chest pain, so bad he thought he was dying, made him vomit, and the only thing that helped was lidocaine in the emergency room. The surgeon who did his scope found he has a large haiatal hernia, and referred him to a gastroenterologist for surgery to "correct" it. When they do surgery for a haiatal hernia, you can't ever burp or vomit again. The gastro surgeon talked with my husband for a little bit, asked him about his symptoms, and told him he thought it was his gallbladder. One ultrasound later, super swollen gallbladder packed with stones. They scheduled his surgery and took that bad boy out. The doc said the stomach area is stupid for nerves, meaning that's why a doctor can't tell what's wrong with where it hurts, there have to be other symptoms or clues. His gall bladder never hurt him, but it caused excruciating pain in his sternum. The doc said he had a female patient whose gallbladder pain manifested on the other side under her ribs, opposite the side the gallbladder is on. Why don't they teach this to general doctors!

I had a patient come into one of my urgent care offices with a lump in her hand. She was in a car accident 7 years ago and said she has glass in her hand that was never removed and that she has lived with it for 7 years. She says she has seen multiple physicians including a dermatologist and they all told her that she was crazy.

I admit I thought she was crazy as well, but I had a student with me and I figure, "Oh well, let's open this lump up and see what we find." Normally I would not do this, but this patient was essentially begging me with tears in her eyes since no one believed her. At worst I figured I'd remove a cyst or lipoma. Sure enough, I make a small incision and squeeze and out pops a 3mm piece of glass. She just stared and me and I stared at her. Closed her up. She wrote a super kind review on our website. We normally get s*** reviews because we don't just hand out antibiotics for every cold that comes through the door.

Not a doctor but I work in pathology. I started to have pain in my back and I got to the point I couldn't stand straight. One day at work and I was on the floor from the pain. Went to the ER and told them I think it's my gallbladder. They told me nope, pulled muscle. Sent me away. This kept happening and I started a diary on what I was doing prior to each episode. Classic gallbladder stone symptoms. Back pain that radiates up, happens after eating fatty food including meat, etc. I went to the ER and my personal doctor 6 times and each time, I was told I was pregnant even though the test was negative each time. I kept insisting it was my gallbladder. Finally, I was so sick and crying at work after being discharged from the ER again, telling me that I'm pregnant and to get over it. When my pathologist who specializes in gastric pathology saw me, he took me back to the ER and made them give me a CT scan. Bingo, the gallbladder was blocked. A month later, has surgery and had a lot of little gallstones. I still have my gallbladder in a jar on my desk as revenge.

I told my internal medicine doctor for years I had Hashimoto's. I had all the symptoms, including the weird ones like hiccups, but nothing registered on blood tests. She basically called me an idiot and diagnosed me as bipolar. This went on for 10 years and bipolar medicine made me suicidal.

Finally got old enough to realize I could tell her to f off and find an endocrinologist. He took an ultrasound of my thyroid and it was almost completely dead. I had to get a biopsy to make sure I didn't have cancer. Years later and I'm still dealing with it since there really isn't a way to treat all the symptoms. Medicine helps, though. Bipolar medicine is out of my system, and that's probably the greatest win. My mental health vastly improved!

Last year my mother ran into my internal medicine doctor and she apologized to my mother. Turns out she didn't believe Hashimoto's was a real autoimmune disease...until she also was diagnosed with it.

Not a doctor but I work at a vet office. I can't remember the exact symptoms but an older lady had an older cat who was ADR (ain't doin right) and she was concerned it could possibly have Mercury poisoning. Major eyerolls by the docs and staff but we took blood and sent it off. She had been feeding this cat a can of tuna a day for the past ~15 years. We get the results and ding ding ding, slight mercury poisoning. I don't even remember the treatment but we were all stunned! One of the most memorable times Dr. Google was right.

I come late to the party, but this has got to be one of the weirdest cases of self-diagnosis.

Long story short, in 1984 a previously healthy woman heard voices inside her head saying:

"Please don't be afraid. I know it must be shocking for you to hear me speaking to you like this, but this is the easiest way I could think of. My friend and I used to work at the Children's Hospital, Great Ormond Street, and we would like to help you."

She first went to a psychiatrist, but the voices only stopped for a while. Sometime later, the voices told her to have a brain scan, because she had a tumor in her brain. The woman once again had an appointment with the psychiatrist, and the psychiatrist (in order to reassure her) managed to request a brain scan. The brain scan revealed a meningioma. After consulting with the voices, the woman agreed to undergo surgery to remove the mass.

As soon as the woman regained consciousness after the surgery, the voices told her:

"We are pleased to have helped you. Goodbye."

That was the last time the woman heard the voices.

I correctly self-diagnosed myself with ulcerative colitis when my doctor said it was IBS. Glad to see I am fit to be a pharmacist because that's what I'm studying.

Not a doctor, but it took me four years to get a sleep disorder diagnosed (Delayed Sleep Phase Disorder).

Started being unable to sleep early and wake on time. Went through a million insomnia diagnoses and every management therapy possible. No improvement. I ask doctors if it could be a sleep disorder. Not possible - "too rare, don't exist, your fault", and so on.

Start checking out different sleep disorders. Based on my management therapies and symptoms list, I start ruling them out one by one. Researching your own murky disorder = stupid idea, I knew. But hey, if not a single doctor has been willing to take your case further, what are you to do?

After all, if you've had DSPD, you'd know that severe untreated DSPD can make it hard or impossible to study, work or have a social life at all. Life is kinda at stake here.

I come to the conclusion that it might be DSPD. Not trying to push anything. I've got a symptom history and a detailed sleep diary of over 24 months by this point.

Doctor 1, 2, 3, 4 and 5 in the UK = "You don't know what you're talking about. Go to bed on time."

Doctor 6 begrudgingly allowed me to see a sleep specialist in Oxford.

The sleep specialist takes one look at my sleep history, symptom history, and survey results. Curses the 5 previous doctors for being proud idiots and not allowing me to make an appointment with her earlier. Diagnoses me with DSPD within a single month of testing.

I used to work in a university ER as a medical scribe. One of my physicians would talk about this patient that came in with a headache and stated that felt like he had a clot "right here" and pointed to the side of his head. When the doctor asked why he felt that way, the patient said, "I dunno man, that's just the way I feel." He eventually ordered a rule out head CT for the pt's symptoms, and lo and behold, that mother trucker had a small clot in that region of his brain. He said it was one of the most bizarre things he'd ever seen, and it was a level 1 trauma center too.