Can Long-Term Exposure to Carbon Monoxide Hurt You?

carbon monoxide detector
A carbon monoxide detector is essential to diagnosing the problem. BanksPhotos / Getty Images

You may be concerned about appliances that leak carbon monoxide into your home over a long period of time. What kind of damage can occur and does it cause long-term effects?

Exposure to carbon monoxide over a long period can make you sick—or even kill you. Carbon monoxide poisoning is the most common type of poisoning worldwide. Carbon monoxide is a gas that you cannot taste, smell or see.

It comes from incompletely burning gas, wood, propane, or a number of other fuels. Carbon monoxide is present in smoke, motor exhaust, and smog, among other sources.

Carbon monoxide blocks oxygen from getting to the places it needs to get in your bloodstream. Red blood cells, which usually carry oxygen, consider carbon monoxide way more sexy than oxygen and are 210 times more attracted to it. People with carbon monoxide poisoning die from not getting enough oxygen to their hearts and brains.

Symptoms of Carbon Monoxide Poisoning

Carbon monoxide poisoning is hard to diagnose. The symptoms of carbon monoxide poisoning look a lot like the flu—headache, body aches, fatigue, nausea—but without a fever. This insidious gas affects each person a little differently, so unless healthcare providers suspect carbon monoxide poisoning, they're likely to overlook it.

Levels of carbon monoxide in the blood are easy to measure but drop rapidly.

Just a few hours after starting to breath fresh air, patients' blood levels of carbon monoxide can be quite low. The only way to diagnose carbon monoxide poisoning is to interview the patient; do a good physical assessment, and suspect it for some reason. It's easier to recognize carbon monoxide poisoning when more than one person in the home (or the school, the office, the car, etc.) also show symptoms.

Low-Level Exposure Risks Uncertain

In cases where the first sign of trouble is finding the presence of carbon monoxide before anyone shows symptoms of poisoning, it's natural to wonder what—if any—damage has been done. Unfortunately, there isn't really an answer to that question yet. There are no published studies that tried to identify symptoms in people who were exposed to carbon monoxide but didn't complain of anything. Carbon monoxide affects heart and muscle function in high and low concentrations, but it isn't known if there is any long-term damage from long exposure to low levels. Besides your home appliances, many people have low-level constant exposure from smoking or smog. While those have proven long-term health consequences, carbon monoxide is just one of the components that may be doing the damage.

Stated again, carbon monoxide exposures too low to cause symptoms may damage the body; but medical science just doesn't know how much or in what way.

Long-Term Effects of Carbon Monoxide Poisoning

There is growing evidence that carbon monoxide poisoning bad enough to send you to the hospital leads to problems up to a year later. These include lethargy, forgetfulness, memory loss, changes in your behavior, and other delayed neurologic problems.

Chronic exposure to carbon monoxide can lead to changes in the brain that can be seen with MRI. One study also found an increased risk of diabetes mellitus after carbon monoxide poisoning. Long-term mortality risk is also increased, according to several studies.


Currently, there are no specific treatments for the aftereffects of carbon monoxide poisoning. Physicians just try to treat the symptoms one by one. More research is being done, but until then, paying attention to your mind and body is the best defense. That, and buying a carbon monoxide detector.


Bleecker ML. Carbon monoxide intoxication. Handbook of Clinical Neurology Occupational Neurology. 2015:191-203. doi:10.1016/b978-0-444-62627-1.00024-x.

Huang C-C, Ho C-H, Chen Y-C, et al. Demographic and clinical characteristics of carbon monoxide poisoning: nationwide data between 1999 and 2012 in Taiwan. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 2017;25:70. doi:10.1186/s13049-017-0416-7.

Huang C-C, Ho C-H, Chen Y-C, et al. Increased risk for diabetes mellitus in patients with carbon monoxide poisoning. Oncotarget. 2017;8(38):63680-63690. doi:10.18632/oncotarget.18887.