What are the Symptoms of an Overdose?

An overdose happens when someone consumes a toxic amount of one or multiple drugs, and the effects interfere with their brain and body’s ability to function properly. Any overdose is a medical emergency, so if you think that you or another person is experiencing an overdose, it is critical to call 911 immediately.

Overdose symptoms can vary, and sometimes, it is hard to differentiate between a drug’s relatively less severe side effects and the symptoms of a life-threatening overdose. 

It’s important to know that nearly any substance has the potential to lead to an overdose. Even substances that people regularly consume in daily life can result in an overdose, but it usually requires a large amount.

The types of substances with the highest risk of overdose typically fall into one of the following categories: alcohol, opioids, sedatives, stimulants, cannabis, and synthetic/designer drugs.

People often refer to an alcohol overdose as alcohol poisoning, which happens when the amount of alcohol in the bloodstream is dangerously high. Typically, anything above .16% blood alcohol content (BAC) results in serious symptoms, such as loss of consciousness, blackouts, and impairment of cognitive functioning. However, when someone’s BAC reaches .30%, their body’s ability to function is severely impaired, posing a serious risk of loss of life.

Symptoms of alcohol overdose include:

• Loss of consciousness
• Drowsiness
• Seizures
• Vomiting
• Slowed heart rate
• Irregular breathing
• Clammy/blue skin
• Extreme weakness
• Unable to be woken up
• Mental stupor

Opioids are the leading cause of drug-related overdoses in the United States. These overdoses can be caused by various drugs, including synthetic opiates like fentanyl and heroin, which have consequences ranging from non-fatal to fatal. While non-fatal overdoses outnumber fatalities, the Opioid epidemic continues to be a major threat to public health.

Symptoms of an Opioid overdose include:

• Inability to stay awake
• Snoring/gurgling sounds resulting from impaired breathing
• Loss of consciousness
• Small ‘pinpoint’ pupils
• Vomiting
• Slow/no heart rate
• Slow/no breathing
• Blue/purple skin
• Limp body
• Pale/clammy skin

Sedative overdoses occur when an individual consumes too much medication designed to help people relax or sleep. While many substances can cause a state of sedation when abused, common sedatives include medications such as benzodiazepines, barbiturates, and sleeping pills. Although not everyone has the same sensitivity to different sedatives, most overdoses result from tolerance buildup, incorrect dosage, or mixing these medications with other drugs or alcohol.

Symptoms of sedative overdose include:

• Loss of consciousness
• Drowsiness
• Inability to be woken up
• Slurred speech
• Vomiting
• Slow heart rate
• Slow/no breathing
• Blue skin
• Extreme weakness
• Mental stupor

Stimulants refer to a broad category of substances, with the most well-known being methamphetamines, cocaine, crack cocaine, and amphetamine-based ADHD medications. Generally stimulants have a quick onset once they are consumed, and the effects usually wear off quickly, as well. This pattern often results in continued use that grows over time, which can lead to overdose.

Symptoms of stimulant overdose include:

• Mood swings
• Confusion
• Anxiety or paranoia
• Irritability/aggression
• Tremors
• Vomiting
• Chest pains
• High blood pressure
• Psychosis
• Hallucinations

Though rare, cannabis/marijuana overdose is a real concern for people who use it. Although it is widely perceived as a relatively safe substance, it is important to be aware of the risks associated when someone consumes too much of it.

Symptoms of Cannabis Overdose:

• Respiratory distress
• Anxiety or panic
• Rapid heart rate
• Muscle spasms
• Delirium
• Low blood pressure
• Vomiting
• Paranoia
• Psychosis
• Hallucinations

Synthetic drugs refer to a wide range of manmade drugs. Some of the most common examples include MDMA (Molly, Ecstasy), LSD, Ketamine, and Synthetic cannabinoids (Spice or K2). All of these substances are considered highly dangerous as there is no standardization for, or regulation of, their production. As a result, one tab or dose could contain significantly different chemical properties than another, which makes the risk of overdose very high.

Due to their high potency, overdoses involving synthetic drugs can result in long-term changes to an individual’s psychological function and, in some cases, it can be fatal.

Symptoms of synthetic drug overdose include:

• Rapid breathing
• Anxiety or panic
• Rapid heart rate
• Inability to sleep
• High body temperature
• High blood pressure
• Vomiting
• Seizures
• Psychosis
• Hallucinations

Risk factors for overdoses can include a range of both external and internal influences. Familiarizing yourself with the factors that increase the likelihood of an overdose can help prevent them from occurring.

Some of these factors include:

• Low drug tolerance. Experiencing a reduction in tolerance to the drugs being used, can increase the likelihood of an overdose if the substance is particularly potent or taken in large amounts.
• Means of ingesting the substance. Taking a drug intravenously is associated with an increased overdose risk.
• Mental health issues. Depression is associated with an increase in both fatal and non-fatal overdoses. The presence of post-traumatic stress disorder (PTSD) or other mental health disorders can also increase an individual’s risk of overdose.
• Not knowing the strength or purity of illicit substances.  It is impossible to accurately dose illicit substances since they aren’t regulated as prescription drugs are, making the risk of overdose much higher.
• Mixing drugs. Taking multiple drugs at the same time. This can increase or mask the effects of substances.
• Masking. Taking multiple drugs, or mixing drugs, in an attempt to suppress or disguise the effects of substances.
• The presence of health issues. Certain health conditions, such as cardiovascular issues, can exacerbate the effects and danger of an overdose. In addition, some prescribed medications can interact with substances that are misused.
• Using alone. Taking drugs alone can increase the danger associated with an overdose since no one is available to address overdose symptoms if they appear. 

If you know or suspect that you or someone else is experiencing an overdose, there are some things that you can do to help:

• First, call 911. Explain to the operator that someone is overdosing and tell them the substance(s) that the person took if you know what they were. If the person is unresponsive and/or not breathing, they will give you instructions and walk you through what to do, which may include cardiopulmonary resuscitation (CPR).
• If you suspect that the person has overdosed on opioids, administering Narcan (naloxone) can often reverse the overdose and save a person’s life. It will have no effect if there aren’t opioids in the person’s system. If the person experiencing a suspected overdose does not respond within 2 to 3 minutes after being given naloxone, a second dose should be given. In some instances, the life-saving effects of naloxone can wear off while opioids are still in the system, so it is important to have the person who is overdosing assessed by a medical professional as soon as possible.
• Stay with the person until help arrives.

After someone receives treatment for an overdose, their physician may recommend that they follow up with substance use treatment. There are treatment options for substance use disorder treatment and co-occurring disorders. Learn more about our programs and how they can help you recover from substance use issues.