It Took Me Two Years and Five Doctors to Figure Out What Was Wrong. The Answer Wasn't in My Body.

“How a homeowner spent two winters believing she was depressed, exhausted, and possibly losing her mind — before discovering that the alarm on her ceiling was legally designed to stay silent at the levels actually making her sick.”

By Sofie Andersen

|

Last Updated Mar 3.2025
Title

The first thing I want you to know is that I am not the kind of person who gets sick.

 

I'm 42 years old. I run a household of four. Before all this started, I was the person other people in my life called when they didn't know what to do. 

 

I made the lists. I scheduled the doctors' appointments. I remembered the birthdays.

 

By the second winter, I couldn't remember which day of the week it was without checking my phone.

 

I'm writing this because I read something on Reddit about eighteen months ago that genuinely changed my life, and I keep thinking about how close I came to never seeing it. 

 

If you've been searching for what's wrong with you and not finding it, if you've started to wonder whether the problem is actually you. I want you to read this before you accept that answer.

What I told my husband I thought was happening to me

It started with the kind of tired that doesn't go away after coffee, or sleep, or a weekend off.

 

Then came the headaches. Not migraines, I've had migraines, and these were different. Duller. Always behind the eyes. Worse in the morning, better when I went out for groceries, back again by dinner. I noticed the pattern but didn't think about it.

 

Then I started forgetting things. The kind of forgetting where you walk into a room and lose the entire reason you walked in. Then where you forget the names of people you've worked with for a decade. Then the morning my husband asked me what I wanted for breakfast and I started to cry, because I didn't know.

 

By late January, I had stopped feeling like myself. I told him I thought I was depressed. That made sense, depression runs in my mother's family. I didn't have a reason to be depressed, but that's how depression works, isn't it? It doesn't ask permission.

 

What I actually thought, in the quietest part of my own head, was that something was very wrong with my brain and that I was going to find out, eventually, that it was already too late.

Five doctors. Three diagnoses. Zero answers.

I did the responsible thing. I went to my GP.

 

She took blood. She ran a thyroid panel. Everything came back, in her exact words, "beautifully normal." She gave me a prescription for an SSRI and told me to come back in three months.

 

Three months later, worse, not better. I went back. She referred me to a neurologist.

 

The neurologist ran an MRI. The MRI was clean. He told me what I was experiencing was "very common in women your age" and suggested perimenopause. He referred me to my OB.

 

My OB ran hormone panels. Everything was, again, in normal range. She told me sometimes the body just goes through phases.

 

I saw a sleep specialist (sleep study: unremarkable). I saw a functional medicine doctor who ordered an expensive heavy-metals test (clean) and put me on B12 injections (no change). I started writing things down because I had stopped trusting my own memory of what I'd already tried.

 

My chart, by the end, said: generalized anxiety disorder; possible early perimenopause; rule out chronic fatigue syndrome.

 

What I had actually done is spend eighteen months proving, with bloodwork, that there was nothing measurably wrong inside my body.

 

Which is what you would expect, actually, if the problem was outside it.

The Reddit comment that changed everything

I was up at 3 a.m. one Tuesday in February, I was up at 3 a.m. most nights by then, when I went down a search rabbit hole I had been in many times before.

 

I had typed some version of "chronic brain fog headaches fatigue normal bloodwork" into Google approximately a thousand times. The results were always the same: anxiety, depression, perimenopause, long COVID, mold, Lyme, mast cell, dysautonomia. I had considered, and in some cases tested for, all of them.

 

This time I added one word I had never thought to add before: "home."

 

The third result was a thread on Reddit. A woman my age was describing what was happening to her and what was happening to her was, in detail I will not forget, exactly what was happening to me. She had been told she was depressed. She had been told it was perimenopause. Her MRI was clean. Her thyroid was fine.

 

A reply, dozens of upvotes deep, said this:

“Have you ever tested for low-level carbon monoxide? I don't mean the alarm on your ceiling. I mean an actual numeric monitor. Most home alarms are legally required to ignore CO under 30 PPM. People can have 20 PPM in their bedroom for an entire winter and the alarm never makes a sound. I've seen people lose years of their life to this and the doctors never catch it because they're not looking for environmental causes.”

I read that comment maybe fifteen times.

 

Then I went and looked at the carbon monoxide alarm on my hallway ceiling. The one I had bought at Home Depot when we moved in, that had been sitting up there showing its little green light through fourteen winters.

 

The green light was on. It always was. I had taken it as proof that everything was fine.

What I didn't know about the alarm on my ceiling

What I learned over the next forty-eight hours genuinely shocked me, and I'm someone who reads ingredient labels for a living.

 

The standard household carbon monoxide alarm, the round disk on your ceiling is built to a regulatory standard called UL 2034. UL 2034 was not designed to protect your health. It was designed to prevent fire departments from being overwhelmed by nuisance alarms.

 

Under that standard, the alarm on your ceiling is legally required to not respond at all when carbon monoxide levels are below 30 parts per million. At 70 PPM, it is allowed to wait up to four hours before sounding. At 150 PPM, well over double the threshold. It can wait up to fifty minutes.

 

Those numbers are written into the federal certification. Your alarm isn't broken. It's working exactly the way the standard tells it to work. It's a fire-department alarm. It is not a health monitor.

 

The other thing I learned is what carbon monoxide actually does inside the body. Carbon monoxide binds to your hemoglobin, the part of your blood that carries oxygen. About two hundred times more tightly than oxygen does. Once it's there, it stays there. So if you're breathing in 20 PPM all night, every night, your blood doesn't reset between exposures the way it would with most other things. The carboxyhemoglobin accumulates. Your brain and heart get a little less oxygen, and a little less, and a little less.

 

The medical literature has a name for what comes next. Delayed neurological sequelae. The official symptom list is, almost word for word, the chart my GP wrote in mine: fatigue, headaches, cognitive impairment, mood changes, memory problems, depression-like symptoms.

 

Not depression. Hypoxia. The slow kind. The kind that the doctors don't catch because they're not looking outside your body for the reason your body is starving.

 

The green light on my ceiling alarm meant the unit was receiving electrical current. It did not mean the air was clean. It did not mean the sensor was working. It did not mean anything at all about whether what I was breathing was safe.

 

I had spent fourteen years of my life trusting it.

A detail I'd missed for fourteen winters

We bought our house when our oldest was a baby. The furnace was already old then. We'd had it serviced annually for the first few years, less often after that, and not at all in the last three or four.

 

Our bedroom is directly above the utility room.

 

I want to say I had a feeling about it, but I didn't. I just knew, after reading what I'd read, that I needed actual data numbers, readings, something I could look at  before I went back to my doctors with a new theory.

 

So I bought a low-level monitor. The kind that doesn't just sit silent until something is catastrophically wrong. The kind that shows you what's actually in your air, in real numbers, all the time.

What I plugged in that night

What I ordered was a small plug-in unit, ordered Tuesday, arrived Thursday. It's the size of a phone charger. You put it into a wall outlet. There's a small color screen on the front. It shows three numbers: carbon monoxide, temperature, humidity. The numbers update continuously.

 

I plugged it into the outlet next to my side of the bed at 9 p.m. on a Thursday in late February.

 

When I woke up at 4 a.m, same headache, same brain fog, I rolled over and looked at the screen.

 

The number wasn't zero.

The number that explained everything

It read 22 PPM.

For three nights, I tracked it. The number climbed slowly through the evening, peaked at 22 to 26 PPM around 4 to 5 in the morning, and dropped after I opened the bedroom door and the heater cycled off in the daytime.

 

22 PPM is below the threshold at which my ceiling alarm is legally required to do anything at all. The medical literature lists 20–30 PPM as the range associated, in chronic exposure, with the exact symptom profile I had been carrying around for two winters: cognitive impairment, fatigue, headaches, mood changes, sleep disruption.

 

I cried at 4:30 a.m. looking at the screen. Not because I was scared, although I was, but because for the first time in two years there was a number, on a screen, that told me I was not making it up.

What we found in the basement

We called an HVAC technician the next morning.

 

He pulled the front panel off our furnace, looked at the heat exchanger for about thirty seconds, and said the words cracked heat exchanger. He explained, gently, that this is not unusual on a 18-year-old furnace. He explained that a crack in the heat exchanger lets combustion gases including carbon monoxide, leak from the burn chamber into the air the furnace circulates through your house. Slowly. All night. All winter.

 

He red-tagged the furnace on the spot. We had it replaced within the week.

 

Three weeks after the new furnace was installed, the number on the bedroom monitor stopped climbing at night. It read 0. The next week, also 0. The week after that, also 0.

 

The fatigue lifted gradually. The headaches went first, within about ten days. The brain fog took longer, maybe two months. The depression, what I had spent eighteen months being treated for — was gone by late spring. I have my notebook. I went back and re-read the entries from the worst weeks. I do not recognize the person who wrote them.

Why I'm writing this

I'm writing this because the CDC reports more than 400 deaths from accidental carbon monoxide poisoning in the United States every year, and more than 100,000 emergency room visits, those numbers reflect only the cases where someone recognized what was happening. The chronic, low-level kind almost never makes it into a chart. It gets coded as fatigue, anxiety, depression, perimenopause, brain fog. The way mine did, for two years.

 

The exposures peak in winter, between December and February, when furnaces and heaters are running and houses are sealed up against the cold. Which is exactly when I got sick. Which is exactly when most of the people in that Reddit thread had gotten sick.

 

I cannot tell you that what happened to me is what's happening to you. I'm not a doctor. I am a person who spent two winters thinking she was losing her mind, and who learned late, but not too late that the standard alarm on her ceiling was working exactly the way the regulators built it to work. Silent below 30 PPM. Silent at 22.

 

If you've been searching for the reason you don't feel like yourself, and the bloodwork keeps coming back clean, and the doctors keep telling you it's stress. I'm not telling you the answer is in your air. I'm telling you that the air is one of the few places they aren't going to look.

 

You have to look there yourself. With a number, on a screen, that doesn't go away when you want it to.

Don't Lose Another Winter to a Number You Can't See

If I could go back to the winter I lost, I'd have ordered four the night I read that Reddit comment instead of one. One in the bedroom, one in the basement, one in the kitchen, one upstairs. I'd have had numbers in every room by the second night and I'd have known by the third where the leak actually was. That would have been the difference between losing a winter and losing a weekend.

 

Every order includes:

 

✓ 3-Year Warranty — covered for replacement if the unit fails 

 

✓ 3-Year Money-Back Guarantee — full refund within three years, no questions asked 

 

✓ Free US Shipping on every bundle  

 

✓ 85 dB Alarm — loud enough to wake you from another room

 

Current pricing:

  • 2-Pack — $99.95 ($49.97 each) — Apartments, condos, or one for you and one for an aging parent
  • 4-Pack — $159.95 ($39.99 each) — Full home coverage
  • 8-Pack — $258.95 ($32.37 each) — Your home plus your parents' home

PRTOECT YOUR HOME WITH VOLT PROTECTION™

️🎊 Hurry! Sale Ends Soon ️🎊

00
DAY
00
HRS
00
MIN
00
SEC

ACT NOW And Receive UP TO 
30% OFF Your Order

PROTECT YOUR HOME TODAY 

HIGH 

Risk of Sell-out

|

FREE shipping

Try it today with a 3-Year Money Back Guarantee!

James Smith 

This device is a lifesaver, literally. The setup was a breeze, and I love that it covers multiple threats in one compact unit. The battery backup is a great feature for when the power goes out. Definitely a 5-star essential for any home.

5

Emily Johnson

I feel so much safer having this 3-in-1 detector in my kitchen. It was incredibly easy to plug in, and the digital display is crystal clear. It gives me peace of mind knowing it’s watching for both CO and natural gas leaks. 🏠🙌

5

Elena Rodriguez

I appreciate the sleek design of this detector. It doesn't look bulky on the wall, and the "Natural Gas" detection gave me the confidence I needed after moving into a house with an older stove. Highly recommend for peace of mind! 

🌟🌟🌟🌟🌟

5

Benjamin Brown

I’ve tried a few different brands, but this 3-in-1 detector is by far the most reliable. The voice alarm is loud enough to wake the whole house, and the real-time gas level readings are super helpful. No more second-guessing!

5

Michael Miller

An absolute must-have. The instructions were straightforward, and the test button works perfectly. It’s a small price to pay for the safety of my family. I ended up buying two more for the upstairs bedrooms! 🔒💪

5