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Carbon Monoxide Poisoning: 17 Signs, Symptoms & Timeline

carbon monoxide from car exhaust

Carbon monoxide poisoning can be extremely scary, as carbon monoxide is nearly impossible to notice without a specialized detector. However, if left untreated, staying in an area with carbon monoxide in too high amounts will cause death.

Therefore, it is vital that you know the signs and symptoms of carbon monoxide poisoning. Often, the only way that you’ll know the levels of carbon monoxide are too high is to notice the symptoms associated with too much carbon monoxide.

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The 17 Signs of Carbon Monoxide Poisoning

1. Drowsiness

When you breathe in too much carbon monoxide, you basically starve your body of oxygen. When this occurs in high amounts or over time, serious effects can occur. However, in the beginning, you may only be slightly drowsy. Your body may feel tired since it isn’t getting the energy it needs.

However, drowsiness can also occur for a whole range of reasons. Therefore, we highly recommend understanding the other symptoms, as well.

2. Fatigue

Because your body isn’t getting the energy it needs, you may feel extremely fatigued. Often, this is an early symptom. However, it is often confused with simply being tired or becoming sick with a viral condition.

3. Headache

Many people experience a headache when they are exposed to carbon monoxide. Often, this is because of the other symptoms, such as low blood pressure. However, it is usually one of the first that is really noticeable.

If you are prone to headaches, though, this symptom may not stand out very much.

Man headache
Photo Credit: Pixabay

4. Nausea and Vomiting

Whenever you are exposed to too much carbon monoxide, you may begin to feel generally unwell in your stomach. While some people do feel nausea and vomit, others may just feel a bit sick. Some don’t feel sick at all.

Plus, because this is an extremely common symptom for a whole host of problems, it typically doesn’t prompt anyone to get help.

5. Dizziness

As your brain is deprived of oxygen and your blood pressure lowers, you may begin to feel dizzy. This is rarely seen as a clear sign that something is wrong, though. People can become dizzy for all sorts of reasons. Therefore, it isn’t odd for this symptom to get ignored, as well.

6. Irritability

With so many bad symptoms, many people start feeling bad, as well. While this can be a symptom in itself, it can also be a secondary symptom caused by all the other problems the person is experiencing.

However, some people never experience this symptom at all, especially if they become drowsy and go to sleep instead.

angry man using phone
Photo Credit: Piqsels

7. Confusion

Without proper oxygen, people’s thinking becomes impaired. In this way, they may become confused. Usually, this is minor, such as going into a room and forgetting why they walked in. Sometimes, it can be difficult to notice in yourself, though you may notice it in other people.

Sometimes, the confusion can be quite severe, such as incorrect speech patterns. However, this is rare.

8. Breathing Problems

While you may not know that you aren’t getting enough air, your body does. Therefore, many people with carbon monoxide poisoning begin breathing rapidly. It may feel like you have exerted yourself when you’ve done nothing but sit down.

Often, this is one of the first symptoms that people start to notice. However, because this can also occur with viral illnesses, it isn’t uncommon for this to be overlooked because people believe that they are simply getting a cold.

9. Fainting

Because of a lack of oxygen, people may begin to faint. Usually, this doesn’t occur until much later and after quite a bit of exposure. However, some may be more prone to fainting than others. Luckily, when this occurs earlier, it is often a sign to get help.

old man fallen down from stairs
Image Credit: wavebreakmedia, Shutterstock

10. Hyperactivity

While you’d expect a lack of oxygen to cause fatigue, it causes the opposite in some people. This may be due to the body’s instinct to get away. However, just like with every toxic substance, some people react differently. This is simply one of those ways.

This is especially common in children. Therefore, it sadly causes many parents to overlook the signs of carbon monoxide poisoning.

11. Impaired Judgement

This goes right along with confusion and other thinking problems. Those with a lack of oxygen will be unable to think straight. Therefore, they may be unable to make good decisions. Sadly, this often interferes with people getting help, as they incorrectly judge the dangers of their condition.

12. Low Blood Pressure

One of the more obvious things that carbon monoxide causes is low blood pressure. Often, this symptom is linked with many of the other symptoms. Therefore, it could also be considered an underlying cause.

However, most people do not regularly check their blood pressure at home. So it will often not be recognized until they seek help.

blood presure check
Image Credit: Piqsels

13. Rapid Heartrate

Similarly, carbon monoxide poisoning can also cause a rapid heart rate. This symptom is caused by your body trying to push oxygen to where it is needed. However, because you aren’t breathing in enough oxygen, your body is having a hard time getting it everywhere it needs. Therefore, your heart will speed up to compensate.

Sometimes, those affected will notice this symptom, but it often goes unnoticed until they seek help.

14. Shock

Eventually, most people will go into shock if they do not lose consciousness first. Their body begins to shut down due to the lack of oxygen. While it is normally obvious that something is wrong at this point, the person usually is unable to get help.

Of course, if anyone else is around, it will become very obvious that something is wrong at this point.

15. Unconsciousness

Usually, most people will lose consciousness as the poisoning progresses. Often, people feel drowsy and may even lay down to go to sleep before they technically “pass out.” Many people may not even realize something is wrong when someone becomes unconscious—until they try to wake them.

sick girl fallen on the floor
Image Credit: bCGN089, Shutterstock

16. Convulsions

Some people convulse due to the lack of oxygen. However, this does not always occur. Instead, the person may simply lose consciousness and never wake back up. When someone convulses, though, it is an obvious sign that something is wrong.

However, at this point, many people aren’t thinking clearly enough to get outside and get help.

17. Coma

Once the condition has progressed, it is very common for people to not wake back up. Often, their brain will be damaged considerably by this point, which makes it difficult for them to return to normal functioning. After reaching this stage, someone might not wake back up even if they get proper medical care.

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Carbon monoxide poisoning is completely preventable. However, many of the symptoms caused by this condition are also caused by viral infections so, in the early stages, many people simply think they are getting sick. Often, this leads to a considerable delay in getting help.

Animals can also get symptoms of carbon monoxide poisoning. Because many pets are small, they often progress faster than humans. People may notice that their pets seem weak or unresponsive before they begin to show symptoms. In this way, dogs often prompt people to get help.

Featured Image Credit: ketrinbell, Shutterstock


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