Preview in new tab Identifying an overdose may be crucial to getting someone the help they need, but it’s not always easy to spot. An overdose isn’t always dramatic, like when someone is poisoned in a movie. It can look like someone falling asleep or quietly losing consciousness. In any circumstance when someone’s life may be in jeopardy, it’s best to call for a medical professional if there is any doubt. Drug overdose symptoms will depend on the drug that’s being used. In many overdose cases, more than one drug is used at the same time. Here are some of the most common drugs that can cause potentially dangerous overdoses and the symptoms they may present: Central nervous system depressants are drugs that slow down the functioning of the nervous system to cause a physical and psychological relaxing feeling or to facilitate sleep. Alcohol and prescriptions like benzodiazepines are in this category. Depressants taken in high doses will slow down the nervous system to the point that it starts to shut down vital functions. It can also cause gastrointestinal distress, dehydration, and psychological effects. Nausea and vomiting are common with alcohol. Vomiting and frequent urination can lead to dehydration, which may present with dizziness, clammy skin, and a flushed complexion. Depressants can cause memory impairment, loss of coordination, and cognitive impairment. An overdose may include these side effects, and a person may have trouble sitting up, communicating, or following a line of thinking. Depressants may also cause someone to lose consciousness or struggle to maintain consciousness. They may also be unresponsive to someone trying to wake them up. Uncontrollable rapid eye movements are also common. Potentially dangerous symptoms may include seizures, slow or irregular breathing, and hypothermia. If someone is breathing very slowly and their body temperature is very low, they will need medical attention as soon as possible. Central nervous system stimulants are drugs that increase activity in the nervous system and excite a user physically and mentally. Stimulant drugs include prescriptions like amphetamine and illicit drugs like methamphetamine and cocaine. Stimulants are misused for their ability to induce feelings of powerful euphoria and extreme confidence. Stimulants can also cause increased wakefulness, racing thoughts, increased body temperature, and heart palpitations. Side effects of potent stimulants like cocaine include sweating, anxiety, tremors, hallucinations, and chest pains. During an overdose, strong impacts can cause extreme side effects such as panic attacks, seizures, confusion, dangerous cardiac symptoms, and a condition called stimulant psychosis. This psychosis is marked by a disconnection with reality that may include visual or auditory hallucinations or delusions. Stimulant overdose can become dangerous when heart palpitations lead to heart failure, stroke, or heart attacks. Increased sweating and vomiting may also lead to dehydration that can add to dangerous side effects. Psychological symptoms can also be potentially life-threatening. Paranoia, hallucinations, and reckless behavior can lead to accidents and injuries. Stimulants can cause more pronounced overdose symptoms like tremors, seizures, or chest pains. If someone passes out suddenly, or if they start to shake or complain of chest pains, call for emergency service immediately. Opioids can cause similar symptoms to depressants during withdrawal. Opioids can cause loss of consciousness, lowered awareness of surroundings, slowed breathing, and confusion. Dangerous overdose symptoms usually involve slowed or stopped breathing, leading to oxygen deprivation. The prevalence of opioid use issues has led to an epidemic of opioid overdose deaths with 46,802 opioid overdose deaths occurring in 2018. The prevalence of opioids has also increased polydrug use. Polydrug use may involve mixing drugs with similar or opposing effects. Unfortunately, polydrug use is very common among dangerous overdoses. Mixing depressants and opioids can potentiate negative side effects, leading to an overdose with lower doses of each individual drug. If you start to see overdose signs but you know the person hasn’t taken a dose that would normally be too high for them, don’t write it off. They may have another drug in their system. Stimulants and opioids can mask each other’s effects, making it harder to tell if someone has overdosed.