Mercury poisoning

What it is

From: Orphanet

Mercury poisoning is caused mainly through ingestion or inhalation of any of the 3 forms of mercury, elemental, organic, and inorganic. Exposure to elemental mercury affects the pulmonary (inhalation of mercury vapors causes coughing, chills, fever, shortness of breath), dermatological (mild swelling, vesiculation, scaling, irritation, urticaria, erythema and allergic contact dermatitis accompanied by pain), and peripheral and central nervous (CNS) systems (depression, paranoia, extreme irritability, hallucinations, inability to concentrate, memory loss, hands, head, lips, tongue, jaw and eyelids tremors, weight loss, perpetually low body temperature, drowsiness, headaches, insomnia, fatigue). Exposure to inorganic mercury generally causes development of a metallic taste, local oropharyngeal pain, nausea, vomiting, bloody diarrhea, colic abdominal pain, renal dysfunction and, neurologic abnormalities; while that to organic mercury can lead to delayed neurotoxicity.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal cerebral white matter morphology · Frequent (79-30%)

An abnormality of the cerebral white matter.

Acute kidney injury · Frequent (79-30%)

Sudden loss of renal function, as manifested by decreased urine production, and a rise in serum creatinine or blood urea nitrogen concentration (azotemia).

Anorexia · Frequent (79-30%)

Lack of desire to eat (loss of appetite).

Confusion · Frequent (79-30%)

Lack of clarity and coherence of thought, perception, understanding, or action.

Dyspnea · Frequent (79-30%)

Difficult or labored breathing. Dyspnea is a subjective feeling only the patient can rate, e.g., on a Borg scale.

Dystonia · Frequent (79-30%)

An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk.

Episodic abdominal pain · Frequent (79-30%)

An intermittent form of abdominal pain.

Episodic vomiting · Frequent (79-30%)

Paroxysmal, recurrent episodes of vomiting.

Generalized muscle weakness · Frequent (79-30%)

Generalized weakness or decreased strength of the muscles, affecting both distal and proximal musculature.

Hypertension · Frequent (79-30%)

The presence of chronic increased pressure in the systemic arterial system.

Hypokalemia · Frequent (79-30%)

The concentration of potassium(1+) in the blood circulation is below the lower limit of normal.

Hypotension · Frequent (79-30%)

Low Blood Pressure, vascular hypotension.

Insomnia · Frequent (79-30%)

Persistent difficulty in starting or maintaining sleep, or waking up earlier than desired, despite having adequate opportunities and conditions for sleep.

Loss of consciousness · Frequent (79-30%)

Loss of awareness of oneself or one's surroundings, involving (i) a loss of normal motor control is evident as flaccidity or stiffness, either of which can be accompanied by jerking movements, and postural control is lost so that patients fall if they are in an upright position; (ii) normal responsiveness is lost; and (iii) the patient experiences amnesia for the event. Loss of consciousness my be transitory (e.g., syncope) or prolonged.

Other findings in the same source

From: Orphanet

Additional reported features include Nausea (Frequent (79-30%)); Respiratory distress (Frequent (79-30%)); Respiratory failure (Frequent (79-30%)); Seizure (Frequent (79-30%)); Tachycardia (Frequent (79-30%)); Tremor (Frequent (79-30%)); Interstitial pneumonitis (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Not applicable

Frequency and the population described

From: Orphanet

Point prevalence: 1-9 / 100 000; Europe; Class only.

Which doctor should you see?

The suggested department for discussing Mercury poisoning is Emergency Medicine, with a emergency physician as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• What is the immediate problem that needs stabilisation?
• Which results and discharge instructions should the family keep?
• What follow-up and return precautions are needed after emergency treatment?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Mercury poisoning. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.