Mercury is a highly toxic environmental metal that can lead to mercury toxicity or poisoning when consumed, inhaled, or touched.

Common symptoms of mercury poisoning include muscle weakness, skin rashes, and headaches. Symptoms are influenced by the type and amount of mercury, the age of the person exposed, and the duration of the exposure.

Depending on the type of mercury exposure, mercury toxicity can gradually develop over years or decades, or symptoms can present very suddenly.

Common symptoms associated with mercury toxicity include headache, shortness of breath, nausea, vomiting, metallic taste, and visual disturbances.

Some people may also experience cough, fever, abdominal pain, diarrhea, and increased salivation. Symptoms will vary depending on the type of mercury that caused the exposure.

There are three main types of mercury: organic, inorganic, and elemental mercury. Each type presents with different symptoms.

Organic Mercury Toxicity

Organic mercury is found in coal-burning fumes, paints containing mercury, fish that consume methylmercury (a form of organic mercury), and older antiseptics such as merbromin, which is now banned by the United States Food and Drug Administration (FDA).

Mercury toxicity can occur if a person eats, inhales, or has skin contact with organic mercury for a long period.

Organic mercury poisoning typically develops over years or decades as small amounts of exposure add up. It is also possible to develop health problems after experiencing a single exposure to a large amount of organic mercury.

Symptoms of organic mercury toxicity include:

• Shakes or tremors
• Numbness or pain in parts of the skin
• Difficulty walking
• Metallic taste
• Double vision or blindness
• Memory problems
• Seizures (caused by significant exposures)

Inorganic Mercury Toxicity

Inorganic mercury is found in batteries, chemistry labs, some disinfectants, and the natural mineral red cinnabar. It is poisonous when swallowed. Symptoms may include burning in the stomach and throat, bloody vomiting, and diarrhea.

Inorganic mercury entering the bloodstream can attack the kidneys and brain, causing kidney damage and failure. If a substantial amount of inorganic mercury enters the bloodstream, it can cause diarrhea and kidney failure and lead to excessive blood and fluid loss, which can lead to death.

Elemental Mercury Toxicity

Elemental mercury is found in some electrical switches, glass thermometers, fluorescent light bulbs, dental fillings, and some medical equipment. Unless touched or swallowed, elemental mercury is usually not harmful.

If elemental mercury accidentally enters the air, it can form tiny droplets you may inhale. Breathing in elemental mercury can cause immediate (acute) symptoms, but it can also cause long-term (chronic) symptoms if you breathe in small amounts over time. Depending on how much you inhale, permanent lung damage, long-term brain damage, and death can occur.

Chronic symptoms of elemental mercury toxicity include:

• Metallic taste in the mouth
• Difficulty breathing
• Vomiting
• Cough
• Swollen, bleeding gums

Infants can be exposed to methylmercury in the womb or during breastfeeding. Methylmercury exposure of this kind is typically a result of the pregnant parent’s consumption of fish and shellfish.

Infants who are born to a person with mercury toxicity can experience severe disabilities or developmental effects, which affect their growing brains and nervous systems.

Methylmercury exposure in the womb can severely damage the nervous system, affecting cognitive thinking, memory, language, and fine motor skills—the ability to make precise movements).

It can also affect visual-spatial skills, which is the ability to tell where objects are in space.

Healthcare providers recommend consuming less fish while pregnant to prevent mercury toxicity. High-mercury fish to limit or avoid include swordfish, king mackerel, and tuna.

Small children should also limit fish consumption to prevent potential developmental problems.

Mercury toxicity can sometimes be chronic and last for long periods. Some research shows that chronic mercury toxicity may be mistaken for autoimmune or systemic inflammatory diseases.

Symptoms of chronic mercury toxicity can include:

• Skin rash
• Symptoms that mimic inflammatory bowel disease (IBD), such as diarrhea, abdominal cramps, fever, rectal pain, and loss of appetite
• Metallic taste in the mouth
• Breathing difficulty
• Vomiting
• Cough
• Swollen, bleeding gums

If you accidentally inhale, ingest, or your skin comes into contact with mercury, go to your nearest emergency room (ER).

See a healthcare provider or visit your nearest ER if you experience other mercury toxicity symptoms, such as shortness of breath, cough, vomiting, metallic taste, or visual disturbances.

You can also call the national toll-free Poison Help hotline at 1-800-222-1222 from anywhere in the United States.

Mercury toxicity occurs when the body experiences harmful health effects from mercury exposure. It can happen either after immediate exposure or from a buildup of mercury in the body over a longer period.

Mercury toxicity can result from organic, inorganic, or elemental mercury exposure. Each type causes different symptoms, and the severity of symptoms is influenced by factors like the amount of mercury exposure, the age of the person exposed, and the duration of the exposure.

Common symptoms include headache, shortness of breath, nausea, vomiting, metallic taste, and visual disturbances.

If you suspect you may have mercury toxicity, see a healthcare provider for diagnosis and treatment. If you are experiencing immediate symptoms after a known exposure to mercury, go to your nearest ER for medical care and treatment.