Carbon monoxide poisoning - Complications 

Complications of carbon monoxide poisoning 

Prolonged exposure to carbon monoxide can cause serious complications including brain damage, heart problems and death in very severe cases. 

Effects of severe carbon monoxide poisoning include breathlessness, chest pains, seizures (fits) and a loss of consciousness. The severity depends on the amount of CO gas you have been exposed to and how long you have been exposed to it for.

Between 10-15% of people who have severe carbon monoxide poisoning develop long-term complications.
Some of which are described below.

Brain damage

Prolonged exposure to CO gas can cause memory problems and difficulty concentrating. It can also cause vision loss and hearing loss.

In rare cases, it can cause Parkinsonism, which is characterised by tremors (shaking), stiffness and slow movement.

(Parkinsonism is not the same as Parkinson's disease, which is a degenerative neurological (brain) condition linked to ageing.)

Heart disease

Coronary heart disease is another serious condition that can develop as a result of long-term exposure to CO gas.

Coronary heart disease is where the blood supply to your heart is blocked or interrupted by a build-up of fatty substances (atheroma) in the coronary arteries.

If your blood supply is restricted, you may get angina (chest pains). If the coronary arteries become completely blocked, it can cause a heart attack.

Read more about coronary heart disease.

Harm to unborn babies

Prolonged exposure to CO gas can also damage an unborn child. Infants exposed to CO gas during pregnancy are at risk of:

  • low birth weight
  • perinatal death (stillbirth and death that occurs within the first four weeks of birth)
  • behavioural problems 

Page last reviewed: 17/04/2012

Next review due: 17/04/2014


How helpful is this page?

Average rating

Based on 19 ratings

All ratings

Add your rating


Workplace health

Improve your health at work, with tips on dealing with stress, RSI, back pain, exercise and healthy lunches