Overdose Symptoms: What to Do, When to Call Emergency Services, and How to Use Naloxone

Overview

An overdose happens when a substance overwhelms the body. It can involve prescription medicines, over-the-counter products, alcohol, street drugs, or combinations of substances. The danger may be obvious, such as collapse or stopped breathing, or less clear, such as extreme sleepiness, confusion, vomiting, or unusual behavior.

You do not need to identify the substance before asking for help. If someone cannot be awakened, is breathing abnormally, has a seizure, or appears seriously ill, call emergency services immediately. If you are in the United States or Canada, call 911; elsewhere, use the local emergency number. Put the phone on speaker so you can follow the dispatcher’s instructions.

Common overdose symptoms can include:

• Unresponsiveness or inability to wake the person
• Slow, shallow, irregular, or stopped breathing
• Gurgling, choking, snoring, or gasping sounds in an unresponsive person
• Blue, gray, pale, or clammy skin, especially around the lips or fingertips
• Very small pupils, which can occur with opioid poisoning
• Vomiting, choking, severe confusion, agitation, or unusual drowsiness
• Seizure, collapse, chest pain, dangerously high temperature, or severe difficulty breathing

Symptoms vary by substance. Stimulant toxicity may involve agitation, overheating, chest pain, or seizures, while sedatives and opioids more often cause excessive sleepiness and slowed breathing. Alcohol, opioids, and sedatives can be especially dangerous in combination. Treat any serious or uncertain situation as an emergency rather than waiting for symptoms to become unmistakable.

For more detail about risk factors, see the overdose risk factors guide. If the person has taken a substance but is awake and stable, Poison Control or a local poison information service may provide substance-specific advice; use emergency services first for severe symptoms.

Checklist by scenario

If the person is unconscious or breathing abnormally

1. Check the scene. Do not enter an unsafe area or handle unknown powders, needles, or chemicals without protection. Move away from traffic, fire, or other immediate hazards if you can do so safely.
2. Try to wake the person. Speak loudly and tap the shoulder. Do not shake violently or put anything in the person’s mouth.
3. Call emergency services. Report that the person is unresponsive or not breathing normally and give the location. Tell the dispatcher what you know about possible substances, including alcohol or prescription medicines.
4. Give naloxone if opioid involvement is possible. Naloxone is designed to reverse opioid effects and will not reverse non-opioid causes of overdose. It is generally safe to give when opioid exposure is uncertain, and it does not replace emergency care.
5. Support breathing. Follow the dispatcher’s instructions. If the person is not breathing normally and you are trained and willing, provide rescue breaths and CPR as directed. If an automated external defibrillator is available, use it according to its prompts.
6. Place a breathing person on their side. The recovery position can help reduce choking risk. Continue watching their breathing and be prepared to begin CPR if it stops or becomes abnormal.

How to use naloxone

Use the product according to its package instructions because devices differ. For a common nasal spray, remove the device from its packaging, place the tip in one nostril, and press the plunger firmly. Call emergency services before or immediately after giving it. If there is no response after the interval stated in the product instructions, give another dose if available and continue following dispatcher guidance. More than one dose may be needed, particularly when potent opioids or multiple substances are involved.

After naloxone, the person may wake suddenly, become confused, upset, or experience withdrawal symptoms. Keep the person safe, continue monitoring breathing, and do not allow them to use more drugs. Naloxone can wear off before the opioid has left the body, so a person who improves still needs urgent medical assessment.

If the person is awake but may have taken too much

• Stay with them and keep them in a safe position, preferably sitting or lying on their side if drowsy or nauseated.
• Call emergency services for serious symptoms, worsening drowsiness, breathing changes, chest pain, seizure, severe confusion, or any uncertainty about safety.
• Do not make them vomit, give them food or drink, or try to counteract one substance with another.
• Keep medication containers, packaging, or other available information for responders. Do not delay the call while searching for details.

If a seizure occurs

Clear nearby objects, protect the person’s head, and time the seizure. Do not restrain them and do not place anything in their mouth. When the seizure ends, check breathing and place them on their side if they are breathing. Call emergency services for a first seizure, repeated seizures, a seizure lasting longer than the emergency dispatcher advises, injury, breathing problems, pregnancy, or suspected poisoning.

What to double-check

• Breathing, not just a pulse: Occasional gasps, snoring, or gurgling in an unresponsive person are not normal breathing.
• Location access: Unlock the door, turn on lights, and send someone to meet responders if possible.
• Substance information: Note what may have been taken, when, and whether alcohol or other medicines were involved. Never delay emergency care to collect evidence.
• Naloxone supply: Check where it is stored, whether the package is intact, and whether household members know how to use it. Keep it accessible rather than locked away in an emergency.
• Personal safety: Avoid contact with bodily fluids and unknown substances. Use gloves or other barriers when available, especially during rescue breathing.
• Ongoing observation: Improvement does not mean the emergency is over. The person can become unresponsive again, especially after naloxone wears off.

For guidance about what happens after naloxone, read what to do after Narcan works. If the situation involves a child, pregnancy, a serious medical condition, or an unknown chemical, tell the dispatcher or poison specialist immediately.

Common mistakes

• Waiting for certainty: You do not have to prove an overdose before calling. Unresponsiveness or abnormal breathing is enough.
• Assuming someone is sleeping: Try to wake them and check breathing. A person who cannot be awakened may be dying.
• Leaving the person alone: Do not leave to find the substance, get water, or avoid embarrassment. Send another person when possible.
• Inducing vomiting: Vomiting can cause choking and usually does not solve the poisoning.
• Using home remedies: Cold showers, coffee, walking, or stimulants do not reliably reverse an overdose and can add danger.
• Stopping after one naloxone dose: Continue monitoring and follow emergency instructions. Additional doses may be needed.
• Delaying care after recovery: Waking up is not the same as being medically safe. Naloxone and other temporary changes can wear off.

For a related decision guide, see Poison Control versus 911. If the crisis is primarily emotional or involves thoughts of self-harm without immediate physical danger, 988 and 911 options may help clarify which support to contact; immediate medical symptoms still require emergency services.

When to revisit

Revisit this checklist before a new prescription, after a change in substance use, when someone in the household returns from treatment or incarceration, or whenever naloxone is obtained. Review it with trusted friends, caregivers, and household members so one person is not the only one who knows what to do.

Keep naloxone in an accessible place and learn where to obtain replacement doses through local pharmacies, community programs, or health services. Recheck the package instructions when the product or device changes. Update emergency contacts, the address shared with responders, and any information about medicines or allergies.

If an overdose has occurred, medical follow-up can address injuries, withdrawal, medication interactions, safer-use planning, and treatment options. Recovery support may include counseling, medications for substance use disorders, peer support, or a higher level of care. See the low-cost addiction treatment guide for care-navigation ideas and the PAWS guide for post-acute withdrawal information.

Printable response checklist: Check safety; try to wake the person; call emergency services; give naloxone if opioid exposure is possible; support breathing and provide CPR as directed; place a breathing person on their side; stay until help arrives; and share what was taken if known. When in doubt, call for help early.