One symptom of carbon monoxide poisoning is the development of Mees lines on the finger - and toe - nails.

Carbon monoxide poisoning has certain symptoms in order to detect its presence but development of mees lines on the figer and toe nails does not include on its symptoms. Mees lines appears if the person experience poisoning of thallium, arsenic or other heavy metals. Mees lines also appear if the person is experiencing or suffering from renal failure.