The symptoms of poisoning depend on the substance and the amount you take in. Some poisonous substances, such as carbon monoxide, interfere with the blood's ability to carry oxygen. Others, such as bleach, burn and irritate the digestive system. Parents and carers should be aware of sudden, unexplained illness in young children, particularly if they're drowsy or unconscious, because poisoning could be the cause. Seek immediate medical advice if you think someone has swallowed a poisonous substance. Find out what to do if you think someone has been poisoned. General symptoms General symptoms of poisoning can include: feeling and being sick diarrhoea stomach pain drowsiness, dizziness or weakness high temperature chills (shivering) loss of appetite headache irritability difficulty swallowing (dysphagia) breathing difficulties producing more saliva than normal skin rash blue lips and skin (cyanosis) burns around the nose or mouth double vision or blurred vision mental confusion seizures (fits) loss of consciousness coma, in severe cases https://www.nhs.uk/conditions/poisoning/symptoms/