Poisoning is when a person is exposed to a substance that can damage their health or endanger their life.

Most cases of poisoning happen at home, and children under 5 have the highest risk of accidental poisoning.

In some cases the person intentionally poisons themselves as a deliberate act of self-harm.

Signs and symptoms of poisoning

The symptoms of poisoning will depend on the type of poison and the amount taken in, but general things to look out for include:

  • being sick
  • stomach pains
  • confusion
  • drowsiness and fainting fits

If a child suddenly develops these symptoms, they may have been poisoned, particularly if they're drowsy and confused.

What to do

If you suspect that someone has taken an overdose or has been poisoned, do not try to treat them yourself. Get medical help immediately.

If they do not appear to be seriously ill, call NHS 111 Wales for advice.

If they're showing signs of being seriously ill, such as being sick, loss of consciousness, drowsiness or seizures (fits), call 999 to request an ambulance or take the person to your local A&E department.

In serious cases, it may be necessary for the person to stay in hospital for treatment. Most people admitted to hospital because of poisoning will survive.

Types of poisons

Poisons can be swallowed, absorbed through the skin, injected, inhaled or splashed into the eyes.

An overdose of medicine is the most common form of poisoning in the UK. This can include both over-the-counter medicines, such as paracetamol, and prescription medications, such as antidepressants.

Other potential poisons include:

  • household products, such as bleach
  • cosmetic items, such as nail polish
  • some types of plants and fungi
  • certain types of household chemicals and pesticides
  • carbon monoxide
  • poorly prepared or cooked food, and food that's gone mouldy or been contaminated with bacteria from raw meat (food poisoning)
  • alcohol, if an excessive amount is consumed over a short period of time (alcohol poisoning)
  • recreational drugs or substances
  • medicines prescribed for pets

Snakes and insects, such as wasps and bees, are not poisonous, but their bites or stings can contain venom (toxin).

Preventing poisoning

There are several things you can do to reduce your or your child's risk of poisoning.

These include carefully reading the patient information leaflet that comes with your medicine and making sure that any poisonous substances are locked away out of the sight and reach of your children.


The symptoms of poisoning depend on the substance and the amount 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're drowsy or unconscious, because poisoning could be the cause.

Seek immediate medical advice if you think someone has swallowed a poisonous substance.

General symptoms

General symptoms of poisoning can include:

  • feeling and being sick
  • diarrhoea
  • stomach pain
  • drowsiness, dizziness or weakness
  • high temperature
  • chills (shivering)
  • loss of appetite
  • headache
  • irritability
  • difficulty swallowing (dysphagia)
  • breathing difficulties
  • producing more saliva than normal
  • skin rash
  • blue lips and skin (cyanosis)
  • burns around the nose or mouth
  • double vision or blurred vision
  • mental confusion
  • seizures (fits)
  • loss of consciousness
  • coma, in severe cases

Signs of a medicine or drug overdose

Medicine overdoses are the most common type of poisoning in the UK.

If someone takes too much of a medicine, they may experience symptoms specific to the medicine taken, as well as the more general symptoms listed above.

Some of the most common medicines or drugs involved in cases of poisoning are listed below.


Paracetamol is a widely used over-the-counter painkiller.

Specific signs of paracetamol poisoning include:


Aspirin is an anti-platelet medicine that thins the blood and reduces the risk of blood clots forming (arterial thrombosis).

Specific signs of aspirin poisoning include:

Tricyclic antidepressants

Tricyclic antidepressants are used to treat clinical depression, as well as a number of other mental health conditions, such as panic disorder and obsessive compulsive disorder (OCD). Some types of tricyclic antidepressants can also be used to treat nerve pain.

Specific signs of poisoning with tricyclic antidepressants include:

Selective serotonin reuptake inhibitors (SSRIs)

SSRIs are a newer type of antidepressant that are also used to treat mental health conditions such as OCD and anxiety disorder.

Specific signs of SSRI poisoning include:

  • feeling agitated
  • tremor (shaking)
  • uncontrolled movement of the eyes (nystagmus)
  • severe muscle tension

Beta blockers

Beta blockers are used to treat a number of conditions that affect the heart or blood, such as high blood pressure (hypertension), angina and heart failure.

Specific signs of poisoning with beta-blockers include:

  • low blood pressure, which can cause symptoms such as lightheadedness and fainting
  • a slow heartbeat (below 60 beats per minute)

Calcium-channel blockers

Calcium-channel blockers are used for the treatment of high blood pressure and angina.

Specific signs of calcium-channel blocker poisoning include:

  • feeling agitated
  • low blood pressure, which can cause symptoms such as lightheadedness and fainting
  • chest pain
  • a slow heartbeat (below 60 beats per minute)


Benzodiazepines are a type of tranquiliser often used on a short-term basis to treat anxiety and sleeping problems (insomnia).

Specific signs of poisoning with benzodiazepines include:

  • co-ordination and speech difficulties
  • uncontrolled movement of the eyes (nystagmus)
  • shallow breathing
  • drowsiness


Opioids are a type of stronger painkiller used to treat moderate to severe pain. They include codeine and morphine, as well as the illegal drug heroin.

Specific signs of opioid poisoning include:

  • small pupils
  • shallow breathing
  • drowsiness

Stimulant overdose

If you take too much of a stimulant-like drug, such as cocaine, amphetamine, crack or ecstasy, overdose signs can include:

  • anxiety and paranoia
  • restlessness or agitation
  • hallucinations
  • high temperature
  • chest pain
  • rapid breathing
  • irregular or fast heartbeat

Cannabis overdose

If you smoke (or eat) too much cannabis, you may experience the following symptoms:

  • paranoia
  • hallucinations
  • numbness in your arms and legs

What to do

Being poisoned can be life-threatening. If someone has been poisoned, do not try to treat them yourself – seek medical help immediately.

If they're showing signs of being seriously ill, dial 999 to request an ambulance or take them to your local A&E department.

Symptoms associated with serious poisoning include:

Call NHS 111 Wales for advice if a person who's been poisoned does not appear to be seriously ill.

Helping someone who's conscious

If you think someone has been severely poisoned and they're still conscious, ask them to sit still and stay with them while you wait for medical help to arrive.

If they've been poisoned by swallowing something, try to get them to spit out anything that is remaining in their mouth.

If a harmful substance has splashed onto their skin or clothes, remove any contaminated items and wash the affected area thoroughly with warm or cool water. Be careful not to contaminate yourself in the process.

Helping someone who is unconscious

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

While you're 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 don't fall on their face or roll backwards. This is known as the recovery position.

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.

If the person isn't breathing or their heart has stopped, begin CPR (cardiopulmonary resuscitation) if you know how to.

Poisonous fumes

If you think someone has inhaled poisonous fumes, assess the situation first and do not put yourself in danger.

If the person is conscious, encourage them to make their way out of the contaminated area, if at all possible. Once they're out into fresh air, check to see if they're OK and call 999 if they have signs of serious poisoning.

Dial 999 to request an ambulance if the person is unconscious or unable to get out of the affected area. Do not enter any enclosed areas to remove the person yourself because toxic gases and fumes can be very dangerous if inhaled.

How to help medical staff

Medical staff will need to take a detailed history to effectively treat a person who's 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)
  • why the substance was taken (whether it was an accident or deliberate)
  • how it was taken (for example, swallowed or inhaled)
  • how much was taken (if you know)

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

Medical staff may also want to know:

  • the person's age and estimated weight
  • whether they have any existing medical conditions
  • whether they're taking any medicine (if you know)

The container the substance came in will help give medical staff a clear idea of what it is. If you don't know what caused the poisoning, blood tests may be needed to identify the cause.

Hospital treatment

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

Possible treatments that can be used to treat poisoning include:

  • activated charcoal – is sometimes used to treat someone who's been poisoned; the charcoal binds to the poison and stops it being further absorbed into the blood
  • antidotes – these are substances that either prevent the poison from working or reverse its effects
  • sedatives – may be given if the person is agitated
  • a ventilator (breathing machine) – may be used if the person stops breathing
  • anti-epileptic medicine – may be used if the person has seizures (fits)

Tests and investigations

Investigations may include blood tests and an electrocardiogram (ECG).

A blood test can be used to check the levels of chemicals and glucose in the blood. They may be used to perform a toxicology screen (tests to find out how many drugs or medicine a person has taken), and a liver function test, which indicates how damaged the liver is.

There is more information about liver function tests on the Lab Tests Online UK website.

An ECG is an electrical recording of the heart to check that it's functioning properly.

Further information

For more information about treating specific types of poisoning see:

Deliberate poisoning

If you or someone you know has poisoned themselves as an act of deliberate self-harm or an attempt at suicide, psychiatric help may be necessary.


The most common form of poisoning in the UK is from medicine.

To reduce the risk of accidental poisoning by medicine:

  • always carefully read the patient information leaflet that comes with your medicine and take the exact dose recommended
  • if you're unsure about any of the instructions or have further questions, ask your pharmacist or GP for advice
  • some medicines should not be taken with alcohol or certain types of food – check if this is the case for your medicine
  • some medicines can react unpredictably if taken with other medicines, including herbal remedies – always check before combining different medicines.
  • never take a medicine that's been prescribed for someone else
  • keep all medicines out of reach of children

Keeping children safe

Children under 5 years of age have a particularly high risk of poisoning. To reduce the risk for your children:

  • make sure all medicines, cleaning products, chemicals and potentially harmful cosmetics, such as nail varnish, are locked away out of the sight and out of 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 encouraging children to take medicine (when they're sick), 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 (including vaping equipment and supplies) and tobacco out of the reach of children and do not smoke in front of children
  • button batteries, such as those used in watches and also found in greeting cards, that play a tune, can be easily swallowed, so keep them and the devices that use them out of reach of children
  • some plants can be harmful to children so keep a careful eye on them when they are in your garden or outside in an area where plants grow
  • "tide pods" (small capsules of detergent or liquid washing powder) are both dangerous and easily swallowed – keep on a high shelf or similar where young children cannot get to them
  • whenever possible, buy medicines that come in child-resistant 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

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 keep certain items out of reach 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.

The information on this page has been adapted by NHS Wales from original content supplied by NHS UK NHS website nhs.uk
Last Updated: 08/03/2024 11:15:21