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Page last reviewed: 13/07/2011

Poisoning happens when you take into your body a substance that damages your cells and organs and injures your health.

Poisons are usually swallowed, but they can also be inhaled, splashed onto the skin or eyes, injected or received through a bite (as with snake bites).

Many substances are only poisonous if an abnormally large amount is taken. For example, paracetamol is harmless if you take one or two tablets for a headache, but is poisonous if you take an overdose.

Some substances are so toxic that small amounts can be harmful. For example, breathing in a small amount of carbon monoxide can cause loss of consciousness and death.

Poisoning accounts for more than 7,500 hospital admissions in Ireland each year.

Types of poison

There are lots of different poisonous substances, including medications, household products (such as cleaning products) and some plants and berries (see Causes for a summary of common poisons).

Substances that are not usually thought of as poisons, such as alcohol and tobacco, can also be very harmful.

Common cases

Most cases of poisoning are accidental and occur in the home. Children under five have the highest risk of accidental poisoning (see box, left), although these cases are rarely fatal. Medicines are the most common cause of poisoning in children of this age.

Occasionally, poisoning may be deliberate. For example, a person may attempt to poison themselves by taking an overdose of prescription medication. For more information, see Self-harm.


Most cases of poisoning usually cause minor side effects, such as stomach upset, which settle within a few days. In these cases, hospital admission is not necessary.

People who develop serious symptoms, such as breathing problems or dizziness, or those who have taken a potentially life-threatening overdose of drugs such as painkillers, will need to go to hospital. Most of them will just be observed to make sure their condition does not get worse (see Treatment).

Fatal poisonings are extremely rare.

Page last reviewed: 13/07/2011

Products around the home

Many substances around the home can be posionous. These include:

  • medication, such as painkillers, steroid creams and petroleum jelly,
  • cleaning products, such as bleach, caustic soda and disinfectant,
  • DIY products, such as paint, glue and wallpaper paste,
  • cosmetics, such as baby oil, shampoo and nail varnish remover, and
  • garden products, such as weedkiller and rat poison.

Insects and snakes

Bees and wasps inject poison into your skin when they sting you, which can cause pain, swelling and itchiness (see Health A-Z: insect stings).

Bites from poisonous snakes can cause diarrhoea and sickness (see Health A-Z: snake bites.The adder is the only poisonous snake that lives in the UK.

How severely you are affected by a poisonous bite or sting depends on the amount of venom (poison) injected and whether you are allergic to it.


Most plants that grow in Ireland are harmless and, if eaten, may only cause a mild stomach upset.

Some types of plant can have a more serious effect, so it is important to know what plants are growing in your garden.

If a potentially poisonous plant has been eaten, try to identify it so you can inform medical staff, or take a sample with you to A&E so that it can be identified.


Food can sometimes cause poisoning if:

  • it goes mouldy,
  • it becomes contaminated with bacteria from raw meat, or 
  • it has not been prepared or cooked properly.

For more information, see Health A-Z: food poisoning

Carbon monoxide

Carbon monoxide is a poisonous, odourless gas that is produced by the incomplete burning of fuels, such as gas, wood or petrol. These types of fuels are used in many household appliances, such as heaters and cookers.

If appliances are not regularly serviced and well maintained, carbon monoxide can leak from them without you realising, which can cause loss of consciousness and death.

For more information, see Health A-Z: carbon monoxide poisoning

Page last reviewed: 13/07/2011

If you suspect that someone has swallowed a poisonous substance, call 999 immediately.

The symptoms of poisoning depend on the substance and the amount that you take in.

Some poisonous substances, such as carbon monoxide, interfere with the blood's ability to carry oxygen. Others, such as bleach, burn and irritate the digestive system.

Parents and carers should be aware of sudden, unexplained illness in young children, particularly if they are drowsy or unconscious, as poisoning could be the cause.

General symptoms

General symptoms of poisoning can include:

  • nausea,
  • vomiting,
  • diarrhoea,
  • stomach pain,
  • drowsiness, dizziness or weakness,
  • fever,
  • chills (shivering),
  • loss of appetite,
  • headache or irritability,
  • difficulty swallowing,
  • producing more saliva than normal,
  • skin rash,
  • burns around the nose or mouth,
  • double or blurred vision,
  • seizures (fits), and
  • coma (in severe cases).

Most cases of poisoning cause minor side effects, such as stomach upset, which settle within a few days.

Symptoms of medication overdose

If you take a medication overdose, you may experience any of the specific symptoms below, as well as the more general symptoms above.


  • nausea,
  • vomiting,
  • a general feeling of being unwell,
  • stomach pain,
  • jaundice (yellowing of the skin and the whites of the eyes),
  • confusion,
  • drowsiness, and
  • coma (in severe cases).


  • nausea,
  • vomiting,
  • rapid breathing,
  • tinnitus (ringing in the ears),
  • fever,
  • disorientation,
  • weakness,
  • sweating,
  • stomach pain,
  • seizures, and
  • coma (in severe cases). 

Tricyclic antidepressants

  • excitability,
  • confusion,
  • blurred vision,
  • dry mouth,
  • fever,
  • large pupils,
  • irregular heartbeat,
  • low blood pressure,
  • a rapid heart rhythm
  • seizures, and
  • coma (in severe cases).

Selective serotonin uptake inhibitors (SSRIs)

  • nausea,
  • feeling agitated,
  • tremor (shaking), and
  • nystagmus (uncontrolled movement of the eyes).

In severe cases:

  • high blood pressure and a rapid heart rhythm,
  • confusion, and
  • severe muscle tension.


  • dizziness,
  • low blood pressure, and
  • a low pulse rate (below 60 beats a minute).

Calcium-channel blockers (such as verapamil)

  • drowsiness,
  • confusion,
  • chest pain,
  • low blood pressure,
  • a low pulse rate (below 60 beats a minute),
  • blue skin,
  • breathing problems,
  • seizures, and
  • coma (in severe cases).

Benzodiazepines (mild tranquillisers)

  • drowsiness,
  • weakness,
  • coordination and speech difficulties,
  • low blood pressure,
  • hypothermia (where body temperature drops below 35°C/95°F),
  • shallow breathing, and
  • coma (in severe cases).

Opioids (painkillers)

  • drowsiness,
  • nausea,
  • vomiting,
  • small pupils,
  • shallow breathing,
  • blue skin,
  • seizures,
  • fluid on the lungs, and
  • coma (in severe cases).

Page last reviewed: 13/07/2011

Being poisoned can be life threatening. If someone has swallowed a poisonous substance, do not try to treat them yourself. Get medical help immediately.

Call 999 for an ambulance, or take the person to your local Accident and Emergency department.

How to help the person

If you think someone has swallowed poison and they appear to be unconscious, try to wake them and encourage them to spit out any pills. Do not put your hand into their mouth and do not try to make them sick.

While waiting for medical help to arrive, lie the person on their side with a cushion behind their back and their upper leg pulled slightly forward, so they do not fall on their face or roll backwards.

Wipe any vomit away from their mouth and keep their head pointing down to allow any vomit to escape without them breathing it in or swallowing it.

Do not give them anything to eat or drink.

How to help medical staff

Medical staff will need to take a detailed history to be able to effectively treat a person who has been poisoned. When the paramedics arrive or when you arrive at A&E, give them as much information as you can, including:

  • What substances you think the person may have swallowed.
  • When the substance was taken (how long ago).
  • How it was taken (for example, swallowed).
  • How much was taken (if you know).

Give details of any symptoms that the person has had, such as whether they have been sick.

If they have been sick, collect a sample of their vomit as it may help medical staff to identify the poison.

Medical staff may also want to know:

  • The person's age and estimated weight.
  • Whether they have any existing medical conditions.
  • Whether they are taking any medication (if you know).

If possible, give medical staff the container that the substance came in to give them a clear idea of what it is. If you do not know what caused the poisoning, blood tests may be needed to identify it.

Hospital treatment

Some people who have swallowed a poisonous substance or have overdosed on medication will be admitted to hospital for examination.


Investigations may include blood tests and an electrocardiogram.

  • Blood tests check the levels of chemicals and glucose in your blood. They may be used to perform a toxicology screen (tests to determine how many drugs you have taken) and a liver function test (which indicates how damaged your liver is).
  • An electrocardiogram (ECG) is an electrical recording of the heart to check that it is functioning properly.

Possible treatments

  • Activated charcoal. Healthcare professionals sometimes use activated charcoal (charcoal that has been treated so that it is pure carbon) to treat someone who has been poisoned. The charcoal binds to the poison and stops it from being further absorbed into the blood. 
  • Antidotes. These are substances that either prevent the poison from working or reverse the effects of the poison.
  • Sedatives. These may be given if the person is agitated.
  • A ventilator (breathing machine). This may be used if the person stops breathing.
  • Antiepileptic medicine. This may be used if the person has seizures.

Poisonous fumes: what to do

If you think someone has inhaled poisonous fumes, assess the situation first and do not put yourself in danger. Call for help and, if it is safe to do so, remove the person from the contaminated area.

Before entering the area, take two or three deep breaths and hold your breath until you come out. As soon as you are out of the affected area, call 999.

Check that the person's airway is open (lift their chin with one hand and gently push down on their forehead with the other to tilt the head back) and that they are still breathing (by placing your cheek close to their mouth to feel their breath).

If they are not breathing, begin cardiopulmonary resuscitation (CPR) if you know how. If the person is breathing and conscious, cover them with a blanket and check whether they are breathing every 10 minutes until the ambulance arrives.

Page last reviewed: 13/07/2011

If you have young children, be extra careful when you have guests to stay or when you go to visit other people. If your friends and relatives do not have children, they may not think to keep certain items out of the reach of children and their home is unlikely to be childproof.

Keep an eye on your children at all times and politely ask guests to keep items such as alcohol and cigarettes out of their reach.

Check household appliances

Always ensure that fuel-burning appliances, such as electric fires and heaters, are well maintained and serviced regularly to prevent carbon monoxide poisoning.

Keep rooms containing appliances well ventilated and fit carbon monoxide detectors or alarms in your home.

Do not block air vents, flues or chimneys and do not have indoor fires in rooms that are not well ventilated.

Consider the garden

Know what plants you have growing in your garden or around your home and whether the leaves, berries, flowers or fruit of certain plants are poisonous.

If you have young children, you may want to remove any potentially harmful plants from your garden. Most importantly, make sure your child knows not to put things from the garden in their mouth.

It is a good idea to know what the plants in your garden are called (including their Latin name) so that, if needed, you can give healthcare professionals this information.

Do not keep houseplants that have poisonous leaves, flowers or berries. Even if you put them out of reach, the poisonous parts may fall onto the floor.

Keep items such as barbecue fuel, weedkillers, fertilisers and methylated spirits in the garden shed or garage and make sure that it is locked at all times.

Garden waste

If you have to burn any rubbish, do so in an open area and do not allow the smoke to blow towards your family or neighbours. It is not safe to burn certain plants, treated wood, plastics and old chemical containers because they produce poisonous gases.

Never pour hazardous chemicals down the sink, drain or toilet.

Recycle wherever possible. Contact your local council to find out what facilities they offer for recycling hazardous household and garden waste, such as pesticides, battery acid and weedkillers.

  • Make sure all medicines, cleaning products and chemicals are locked away out of the sight and reach of children.
  • Do not store medicines, cleaning products or chemicals near food.
  • Keep all chemicals in their original containers and never put medicines or chemicals, such as weedkiller, in soft-drinks bottles.
  • When necessary, encourage children to take medicine, but do not refer to tablets as sweets.
  • Do not leave old medicines lying around. Take them to your local pharmacist to dispose of safely.
  • Keep cigarettes and tobacco out of the reach of children and do not smoke in front of children.
  • Small batteries, such as those used for television remote controls, can be easily swallowed, so keep them out of the reach of children.
  • Whenever possible, buy medicines that come in child-proof containers.
  • Rinse out medicine or cosmetic containers and dispose of them in a place where children cannot reach them.
  • Do not take or give medicines in the dark to avoid taking an incorrect dosage.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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