Toxicology and Poison

Definition of Poison

Poison is a substance that is capable of causing the illness or death of a living organism when introduced or absorbed.

"All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy." Paracelsus (1493-1541)


This is a fairly simple statement put in a complex form. Its is stating that all substances can be used to poison someone or used to heal them; its a difference in the quantity of the substance consumed. An example of this is water, if too much is consumed you will get water poisoning and die, but water can cure dehydration and keep you from dying.

Why are poisons difficult to detect?

Many poisons are difficult to detect because the mimic the symptoms of other diseases. Many time this is why many people who are poisoned die before it is discovered that they had been poisoned.




weakness, headache, burning eyes, nausea, abdominal pain, cough, hyperpigmentation, anemia, and death


Arsenic poisoning is normally diagnosed by the hyperpigmentation that occurs on the main trunk and outer extremities, occasionally collecting in mucus membranes making it visible in the mouth and under the tongue.


February 18, 2002

Cynthia Sommer poisoned her marine husband for the veterans benefits and to pay for breast implant surgery. He died and when his organs were donated to research it was found he had elevated levels of arsenic in his liver and kidneys. Cynthia Sommer was tried and convicted of first degree murder and faces a life long sentence with no parole.



paresthesia, hypersalivation, sweating, weakness, headache, in-coordination, tremors, paralysis, seizures, coma, and death


Diagnosis is mainly based on observation and review of recent dietary history.


There aren't any cases involving the poison Tetrodotoxin, most deaths are caused by this poison due to food poisonING and are not intentional.

What parts of the body are tested when looking for poison?

The best place to detect poisoning is in brain tissue, but many times that is unavailable and hard to attain. So the most common place they test when poison is the blood stream. If testing on a post mortem subject the sample will be taken from multiple locations.