Symptoms of arsenic poisoning can be pervasive and yet seemingly undetectable. This is because arsenic poisoning can affect many different organs in the body, and problems with these organs may all appear to be unrelated. A complete physical examination including personal histories and environmental exposures should be considered when attempting to identify arsenic poisoning.

When someone is suffering from arsenic poisoning, he or she may first experience headaches. Later, headaches will transform to a lightheaded sensation. Numbness and a tingly feeling in the hands and feet may also occur at the onset of poisoning.

Other symptoms of arsenic poisoning may include stomach pain, bowel pain, tenderness and pressure on the body, retching, vomiting, excess saliva, green, yellow or blood-streaked vomit, a dry or tight throat, lethargy, thirst and weakness. A hoarse voice, encephalopathy, coma, speech changes or difficulty speaking, diarrhea, a burning sensation while urinating, tenesmus, problems with the anus, cramps, convulsions, cold or clammy sweats, purplish-red skin, a sunken face, red eyes and delirium may indicate poisoning. Elevated liver enzymes, hypotension, shock, congestive heart failure, ventricular arrhythmia, pulmonary edema, renal cortical necrosis and garlicky breath can also present themselves as symptoms. A combination of gastrointestinal, respiratory, cardiovascular, neurologic, renal, hepatic and hematologic symptoms may form and point to symptoms of arsenic poisoning.

It should be noted that not all of these symptoms have to be present to indicate arsenic poisoning. In addition, symptoms of arsenic poisoning may not be obvious if the poisoned person inhaled toxic amounts of arsenic instead of ingesting it. Subsequent symptoms of arsenic poisoning may include health problems that can appear as major illnesses in and of themselves, like keratoses of the feet, lung cancer and skin cancer.

Prolonged exposure to arsenic poisoning may often result in specific arsenic-related symptoms. Cutaneous hyperpigmentation, skin lesions, anemia, lung cancer, skin cancer, hyperpigmentation and hyperkeratosis have been linked to continuous exposure to toxic amounts of arsenic. Neuropathy symptoms are often the first to arise after prolonged exposure.

It goes without saying that a symptom of arsenic poisoning is also death. However, not all doses of arsenic are lethal. The toxicity of arsenic varies and can depend on factors such as solubility, valence state and its originating source. Inorganic compounds of arsenic are generally thought to be more toxic than their organic counterparts. Some arsenic compounds can be up to 500 times as lethal as those that are in their natural forms.