What is the likely prognosis when ingesting mercury?
The prognosis for an individual who has consumed large amounts of methylmercury (e.g., by eating fish contaminated with it) depends on a variety of factors, including:

the amount and duration of exposure to methylmercury;
the age at which symptoms begin to appear;
any pre-existing medical conditions or other risk factors that may make the person more susceptible to its effects;
the specific organs affected by the poisoning;
and any additional exposures or medications the patient might be taking.

In general, however, methylmercury can cause neurological damage in humans if the dose is high enough and the exposure lasts long enough. The severity of the damage will depend on several factors such as how much of the compound was absorbed into the body, the speed of absorption, and the length of time the poison remains in the system.