Learn the identifying signs and symptoms of a drug overdose so that you can get the help you or a loved one needs and possibly save a life. CDC works to prevent drug overdose, the leading cause of injury-related death in the United States. Overdose (OD) happens when a toxic amount of a drug, or combination of drugs overwhelms the body. People can overdose on lots of things, including alcohol, Tylenol, opioids or a mixture of drugs. Ending drug-related overdose deaths through education, medical intervention, and public awareness. An overdose is when you take more than the recommended amount of something, often a medicine or drug. An overdose may result in serious, harmful symptoms or death. When someone experiences an overdose, their body becomes overwhelmed by the toxic effects of the substance they've consumed. Learn more. Find overdose prevention and intervention resources for public health professionals. Information on overdose prevention strategies and partnerships for healthcare professionals. Preventing drug overdose and reducing substance use-related harms is a CDC priority. Overdose is the term used when someone enters into a critical state from ingesting too much of a substance or blend of substances. The word overdose implies that there is a common safe dosage and usage for the drug; therefore, the term is commonly applied only to drugs, not poisons, even though many poisons as well are harmless at a low enough dosage. Overdose happens when someone consumes a toxic amount of one or multiple drugs. An 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.