MSD Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Overview of Poisoning


Gerald F. O’Malley

, DO, Grand Strand Regional Medical Center;

Rika O’Malley

, MD, Grand Strand Medical Center

Reviewed/Revised May 2022 | Modified Sep 2022
Topic Resources

Poisoning is the harmful effect that occurs when a toxic substance is swallowed, is inhaled, or comes in contact with the skin, eyes, or mucous membranes, such as those of the mouth or nose.

  • Possible poisonous substances include prescription and over-the-counter drugs, illicit drugs, gases, chemicals, vitamins, food, mushrooms, plants, and animal venom.

  • Some poisons cause no damage, whereas others can cause severe damage or death.

  • The diagnosis is based on symptoms, on information gleaned from the poisoned person and bystanders, and sometimes on blood and urine tests.

  • Drugs should always be stored in original child-proof containers and kept out of the reach of children.

  • Treatments include supporting the person's body functions, preventing additional absorption of the poison, increasing elimination of the poison, and sometimes giving a specific antidote.

More than 2 million people suffer some type of poisoning each year in the United States. Drugs—prescription, over-the-counter, and illicit—are a common source of serious poisonings and poisoning-related deaths (see Acetaminophen Poisoning Acetaminophen Poisoning Acetaminophen, a common ingredient in many prescription and non-prescription drugs, is safe in normal doses, but severe overdose can cause liver failure and death. People sometimes ingest too... read more and Aspirin Poisoning Aspirin Poisoning Aspirin and related drugs called salicylates, a common ingredient in many prescription and over-the-counter drugs, is safe in normal doses, but severe overdose can cause severe symptoms and... read more ). Other common poisons include gases (for example, carbon monoxide Carbon Monoxide Poisoning Carbon monoxide is a colorless, odorless gas that is produced when many materials are burned and can be toxic when breathed in large amounts Carbon monoxide poisoning is common. Symptoms may... read more ), household products (see Caustic Substances Poisoning Caustic Substances Poisoning Caustic substances are highly acidic or alkaline chemicals that can cause severe burns to the mouth and digestive tract when swallowed. When swallowed, caustic substances can burn all tissues... read more ), agricultural products, plants Plant and Shrub Poisoning Only a few commonly grown plants are very poisonous, but many others have less serious toxic effects. Generally, poisoning is unlikely unless a plant is highly toxic or large quantities are... read more , heavy metals (for example, iron Iron Poisoning Iron is a mineral essential to life, but taking too much iron can cause severe symptoms, liver damage, and even death. Symptoms develop in stages and begin with vomiting, diarrhea, and abdominal... read more and lead Lead Poisoning Lead poisoning affects many parts of the body, including the brain, nerves, kidneys, liver, and blood. Children are particularly susceptible because their nervous system is still developing... read more ), vitamins, animal venom, and foods (particularly certain species of mushroom Mushroom (Toadstool) Poisoning Many species of mushroom are poisonous and can cause different symptoms depending on the type of mushroom. Different species of mushrooms produce different toxins with different effects. Even... read more and bony fish and shellfish Fish and Shellfish Poisoning Certain types of fresh or frozen fish or shellfish may contain toxins that can cause a variety of symptoms. Vomiting and diarrhea ( gastroenteritis) caused by toxins is different from gastroenteritis... read more ). However, almost any substance ingested in sufficiently large quantities can be toxic (poisonous).

Accidental poisoning

Poisoning is the most common cause of nonfatal accidents in the home. Young children, because of curiosity and a tendency to explore, are particularly vulnerable to accidental poisoning in the home, as are older people, often due to confusion about their drugs. Because children often share found pills and substances, siblings and playmates may also have been poisoned. Also vulnerable to accidental poisoning are hospitalized people (by drug errors) and industrial workers (by exposure to toxic chemicals).

Deliberate poisoning

Poisoning may also be a deliberate attempt to commit murder or suicide. Most adults who attempt suicide by poisoning take more than one drug and also consume alcohol. Poisoning may be used to disable a person (for example, to rape or rob them). Rarely, parents with a psychiatric disorder poison their children to cause illness and thus gain medical attention (a disorder called factitious disorder imposed on another Factitious Disorder Imposed on Another Factitious disorder imposed on another is falsifying or producing symptoms of a physical or psychologic disorder in another person. It is usually done by caregivers (typically parents) to someone... read more previously called Munchausen syndrome by proxy).

Symptoms of Poisoning

The symptoms caused by poisoning depend on the poison, the amount taken, and the age and underlying health of the person who takes it. Some poisons are not very potent and cause problems only with prolonged exposure or repeated ingestion of large amounts. Other poisons are so potent that just a drop on the skin can cause severe symptoms.

Some poisons cause symptoms within seconds, whereas others cause symptoms only after hours, days, or even years. Some poisons cause few obvious symptoms until they have damaged vital organs—such as the kidneys or liver—sometimes permanently.

Ingested and absorbed toxins generally cause bodywide symptoms, often because they deprive the body's cells of oxygen or activate or block enzymes and receptors. Symptoms may include changes in consciousness, body temperature, heart rate, and breathing and many others, depending on the organs affected.

Caustic or irritating substances injure the mucous membranes of the mouth, throat, gastrointestinal tract, and lungs, causing pain, coughing, vomiting, and shortness of breath.

Skin contact with toxins can cause various symptoms, for example, rashes, pain, and blistering. Prolonged exposures may cause dermatitis.

Eye contact with toxins may injure the eye, causing eye pain, redness, and loss of vision.

Some Nontoxic Household Products*

  • Adhesives

  • Antacids

  • Bath oil†

  • Bathtub toys (floating)

  • Bleach (household concentration: less than 6% sodium hypochlorite and less than 0.5% sodium hydroxide)

  • Body conditioners

  • Bubble bath soaps (detergents)†

  • Candles

  • Carbowax (polyethylene glycol)

  • Carboxymethylcellulose (dehydrating material packed with film, books, and other products)

  • Castor oil

  • Cetyl alcohol (also called palmityl oil, a substance used in certain cosmetic products such as shampoos and conditioners)

  • Chalk (calcium carbonate)

  • Colognes

  • Contraceptives

  • Corticosteroids (applied to the skin)

  • Cosmetics

  • Crayons

  • Deodorants

  • Deodorizers, spray and refrigerant

  • Diaper rash cream and ointment

  • Dry cell battery (alkaline)

  • Fabric softeners

  • Glow products, such as glow sticks and glow necklaces

  • Glycerol

  • Glyceryl monostearate

  • Graphite

  • Gums (such as acacia, agar, and ghatti)

  • Hand lotions and creams

  • Hydrogen peroxide (3% medicinal)

  • Incense

  • Indelible markers

  • Ink (the amount in a ballpoint pen)

  • Iodide salts

  • Kaolin

  • Lanolin

  • “Lead” pencils (which are really made of graphite)

  • Linoleic acid

  • Linseed oil (not boiled)

  • Magic markers

  • Matches

  • Methylcellulose

  • Mineral oil

  • Modeling clay

  • Newspaper

  • Paint (water color or water-based)

  • Perfumes

  • Petroleum jelly

  • Plant food (household)

  • Polyethylene glycols, such as polyethylene glycol stearate

  • Polysorbate

  • Putty

  • Sachets (essential oils, powders)

  • Shaving creams and lotions

  • Silica (silicon dioxide)

  • Soap and soap products (including hand soap)

  • Spermaceti

  • Starch and sizing

  • Stearic acid

  • Sunscreens

  • Talc (except when inhaled)

  • Titanium dioxide

  • Toothpaste with or without fluoride

  • Triacetin (glyceryl triacetate)

  • Vitamins (children’s multiple with or without iron)

  • Vitamins (multiple without iron)

  • Wax or paraffin

  • Zinc oxide

  • Zirconium oxide

* Almost any substance can be toxic if ingested in sufficient amounts.

† Moderately viscous (thick) substances like oils and detergents are not toxic if ingested but can cause significant lung injury if they are inhaled or aspirated into the lungs.

First Aid for Poisoning

The first priority in helping a poisoned person is for bystanders not to become poisoned themselves.

People exposed to a toxic gas should be removed from the source quickly, preferably out into fresh air, but rescue attempts should be done by professionals. Special training and precautions must be considered to avoid being overcome by the toxic gases or chemicals during rescue attempts. (See also Overview of Incidents Involving Mass-Casualty Weapons Overview of Incidents Involving Mass-Casualty Weapons Mass-casualty weapons are weapons that can produce a mass-casualty incident. Mass-casualty incidents overwhelm available medical resources because they involve so many injured people (casualties)... read more .)

In chemical spills, all contaminated clothing, including socks and shoes, and jewelry should be removed immediately. The skin should be thoroughly washed with soap and water. If the eyes have been exposed, they should be thoroughly flushed with water or saline. Rescuers must be careful to avoid contaminating themselves.

If the person appears very sick, emergency medical assistance (911 in most areas of the United States) should be called. Bystanders should do cardiopulmonary resuscitation First-Aid Treatment for Cardiac Arrest Cardiac arrest is when the heart stops pumping blood and oxygen to the brain and other organs and tissues. Sometimes a person can be revived after cardiac arrest, particularly if treatment is... read more First-Aid Treatment for Cardiac Arrest (CPR) if needed. If the person does not appear very sick, bystanders can contact the nearest poison control center for advice. In the United States, the local poison center can be reached at 800-222-1222. More information is available at the American Association of Poison Control Centers web site ( If the caller knows or can find out the identity of the poison and the amount ingested, treatment can often be initiated on site if this is recommended by the poison center.

Containers of the poisons and all drugs that might have been taken by the poisoned person (including over-the-counter products) should be saved and given to the doctor or rescue personnel. The poison center may recommend giving the poisoned person activated charcoal Prevent absorption of poison before arrival at a hospital and, rarely, may recommend giving syrup of ipecac to induce vomiting, particularly if the person must travel far to reach the hospital. However, unless specifically instructed to, charcoal and syrup of ipecac should not be given in the home or by first responders (such as ambulance personnel). Syrup of ipecac has unpredictable effects, often causes prolonged vomiting, and may not remove substantial amounts of poison from the stomach.

Diagnosis of Poisoning

  • Identification of the poison

  • Sometimes, urine and blood tests

  • Rarely, abdominal x-rays

Identifying the poison is helpful to treatment. Labels on bottles and other information from the person, family members, or coworkers best enable the doctor or the poison center to identify poisons. If labels are not available, drugs can often be identified by the markings and colors on the pill or capsule. Laboratory testing is much less likely to identify the poison, and many drugs and poisons cannot be readily identified or measured by the hospital. Sometimes, however, urine and blood tests may help in identification. Blood tests can sometimes reveal the severity of poisoning, but only with a very small number of poisons.

Doctors examine people to look for signs that suggest a certain type of substance. For example, doctors look for needle marks or track marks suggesting people have injected drugs (see Injection Drug Use Injection Drug Use Drugs may be swallowed, smoked, inhaled through the nose as a powder (snorted), or injected. When drugs are injected, their effects may occur more quickly, be stronger, or both. Drugs may be... read more Injection Drug Use ). Doctors also examine people for symptoms characteristic of certain kinds of poisoning. Doctors look to see whether people have traces of a drug or substance on their skin or whether drug patches for drugs absorbed through the skin may be hidden in skin folds, on the roof of the mouth, or under the tongue.

For certain poisonings, abdominal x-rays may show the presence and location of the ingested substances. Poisons that may be visible on x-rays include iron, lead, arsenic, other metals, and large packets of cocaine or other illicit drugs swallowed by so-called body packers or drug mules (see Body Packing and Body Stuffing Body Packing and Body Stuffing To smuggle illegal drugs across borders or other security checkpoints, people may voluntarily swallow packets filled with drugs or hide those packets in body cavities. If a packet tears, a drug... read more ). Batteries and magnets are also visible on x-rays, as are fangs, teeth, cartilaginous spines and other animal parts that may break off and remain embedded in the body after an animal attack or envenomation.

Drug testing

Kits to identify drugs in the urine can now be bought over the counter. The accuracy of these kits can vary significantly. Thus, results should not be regarded as proof that a certain drug has or has not been taken. Testing is best done in consultation with a professional. If done without a professional, results should be discussed with a professional who has experience with drug testing. The professional can help people interpret test results and draw the appropriate conclusions.

Prevention of Poisoning

In the United States, widespread use of child-resistant containers with safety caps has greatly reduced the number of poisoning deaths in children younger than age 5. To prevent accidental poisoning, drugs and other potentially dangerous substances should be kept in their original containers and the containers kept where children cannot get them. Toxic substances, such as insecticides and cleaning agents, should not be put in drink bottles or cups, even briefly. Other preventive measures include

  • Clearly labeling household products

  • Storing drugs (particularly opioids) and toxic or dangerous substances in cabinets that are locked and out of the reach of children

  • Using carbon monoxide detectors

Expired drugs should be disposed of by mixing them with cat litter or some other substance that is not tempting and putting them in a trash container that is inaccessible to children. People can also call a local pharmacy for advice on how to properly dispose of drugs. All labels should be read before taking or giving any drugs or using household products.

Limiting the amount of over-the-counter pain reliever in a single container reduces the severity of poisonings, particularly with acetaminophen, aspirin, or ibuprofen. The identifying marks printed on pills and capsules by the drug manufacturer can help prevent confusion and errors by pharmacists, health care practitioners, and others.

Did You Know...

  • In the United States, the local poison center can be reached by dialing 1-800-222-1222.

Treatment of Poisoning

Some people who have been poisoned must be hospitalized. With prompt medical care, most recover fully.

The principles for the treatment of all poisonings are the same:

  • Support vital functions such as breathing, blood pressure, body temperature, and heart rate

  • Prevent additional absorption

  • Increase elimination of the poison

  • Give specific antidotes (substances that eliminate, inactivate, or counteract the effects of the poison), if available

  • Prevent reexposure

The usual goal of hospital treatment is to keep people alive until the poison disappears or is inactivated by the body. Eventually, most poisons are inactivated by the liver or are passed into the urine.

Provide supportive care

Poisoning often requires treatment, termed supportive care, to stabilize the heart, blood pressure, and breathing until the poison disappears or is inactivated. For example, a person who becomes very drowsy or comatose may need a breathing tube inserted into the windpipe. The tube is then attached to a mechanical ventilator Mechanical Ventilation Mechanical ventilation is use of a machine to aid the movement of air into and out of the lungs. Some people with respiratory failure need a mechanical ventilator (a machine that helps air get... read more , which supports the person’s breathing. The tube prevents vomit from entering the lungs, and the ventilator ensures adequate breathing.

Treatment also may be needed to control seizures, fever, or vomiting. If a poison causes a high fever, the person may need to be cooled, for example, with a cooling blanket, or sometimes by applying cool water or ice to the skin.

Remove poison from the eyes and skin

Poisons in the eyes or on the skin usually should be washed off with large amounts of salt (saline) solution, or tap water. Sometimes soap and water is used on the skin.

Prevent absorption of poison

Very few swallowed poisons are absorbed so quickly that measures cannot be tried to keep them out of the bloodstream. However, such measures are effective only for certain poisons and situations.

Stomach emptying (inducing vomiting or stomach pumping), once commonly done, is now usually avoided because it removes only a small amount of the poison and can cause serious complications. Stomach emptying rarely improves a person's outcome. However, stomach pumping may be done very rarely if an unusually dangerous poison is involved or if the person appears very sick.

In this procedure, a tube is inserted through the mouth into the stomach. Water is poured into the stomach through the tube and is then drained out (gastric lavage). This procedure is repeated several times. If people are drowsy because of the poison, doctors usually first put a plastic breathing tube through the mouth into the windpipe (endotracheal intubation). Endotracheal intubation helps keep the gastric lavage liquid from entering the lungs.

Doctors often used to give syrup of ipecac, a drug that causes vomiting, to children who swallowed poisonous substances. However, this treatment did not often remove significant amounts of the swallowed substance. Now doctors use ipecac only for substances that are highly toxic and when it would take a long time to get the person to the emergency department. In the hospital, doctors do not give syrup of ipecac to empty the stomach because its effects are inconsistent.

Activated charcoal is sometimes given in hospital emergency departments to people who have swallowed poisons. Activated charcoal binds to the poison that is still in the digestive tract, preventing its absorption into the blood. Charcoal is usually taken by mouth if the person is alert and cooperative. Introducing activated charcoal through a tube placed in the nose or mouth in people who are either uncooperative or lethargic is not recommended. Sometimes doctors give charcoal every 4 to 6 hours to help cleanse the body of the poison. Not all poisons are inactivated by charcoal. For example, charcoal does not bind alcohol, iron, or many household chemicals.

Whole-bowel irrigation is a treatment method designed to flush a poison from the digestive tract. It is used only occasionally, for example, for serious poisoning caused by poisons that get stuck in the digestive tract or need to be moved physically (such as packets of hidden, smuggled drugs) or poisons that are absorbed slowly (such as some sustained-release drugs) or not absorbed by activated charcoal (such as iron and lead).

Increase elimination of poison

If a poison remains life threatening despite the use of charcoal and antidotes Antidotes Poisoning is the harmful effect that occurs when a toxic substance is swallowed, is inhaled, or comes in contact with the skin, eyes, or mucous membranes, such as those of the mouth or nose... read more , more complicated treatments that remove the poison may be needed. The most common treatments are hemodialysis and charcoal hemoperfusion.

In charcoal hemoperfusion, a person's blood is passed over activated charcoal to help eliminate the poisons (see table Hemofiltration and Hemoperfusion: Other Ways of Filtering the Blood Hemofiltration and Hemoperfusion: Other Ways of Filtering the Blood Hemofiltration and Hemoperfusion: Other Ways of Filtering the Blood ).

For either of these methods, small tubes (catheters) are inserted into blood vessels, one to drain blood from an artery and another to return blood to a vein. The blood is passed through special filters that remove the toxic substance before being returned to the body.

Alkaline diuresis is sometimes used. With this procedure, a solution containing sodium bicarbonate (the chemical in baking soda) is given by vein to make the urine more alkaline or basic (as opposed to acidic). This can increase the amount of certain drugs (such as aspirin and barbiturates) excreted in the urine.


Although most poisons and drugs do not have specific antidotes (unlike the popular perception from TV and movies), some do. Some common drugs that might require specific antidotes include acetaminophen (antidote is N-acetylcysteine Treatment Acetaminophen, a common ingredient in many prescription and non-prescription drugs, is safe in normal doses, but severe overdose can cause liver failure and death. People sometimes ingest too... read more ) and opioids such as heroin and fentanyl (antidote is naloxone). Some poisonous bites and stings also have antidotes (see Snakebites Snakebites Venomous snakes in the United States include pit vipers (rattlesnakes, copperheads, and cottonmouths) and coral snakes. Severe envenomation can cause damage to the bitten extremity, bleeding... read more Snakebites ). Not everyone who has been exposed to a poison requires its antidote. Many people recover on their own. But with severe poisoning, antidotes can be lifesaving.


Mental health evaluation

More Information

The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

quiz link

Test your knowledge

Take a Quiz!