We have always been told to take care of our hearts, and to do what we can to avoid cancer-causing agents, habits or behavior. Heart disease and cancer have long been known as the leading causes of death for those under the age of 80 in the United States.

While fewer Americans are dying from both of these — those gains are being offset by a rising number of drug overdose deaths, according to the Centers for Disease Control and Prevention.

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The agency just released its top five causes of preventable deaths in the U.S. between 2010 and 2014. These five are heart disease, cancer, chronic lower respiratory disease, stroke, and a broad category called “unintentional injuries.”

Nearly two-thirds of deaths in the United States are caused by these five diseases or conditions.

This last category of “unintentional injuries” is critical: Health officials have been keeping track of drug overdoses, of which the country is said to now be facing an epidemic. The CDC reported more overdose deaths in 2014 than in any year on record — listing 45,331 accidental deaths as “preventable,” up from 36,836 in 2010.

That number is believed to have gone up since.

Where cancer is concerned, there remains hope — the number of expected deaths from the disease fell by 21,234. Still, the overall number of deaths related to cancer rose by 15,233 in the five-year period despite a rapidly aging population.

Related: Mother Takes Own Life After Son’s Overdose

In England and Wales, the leading cause of death has shifted. While heart disease has long been the main killer, dementia has overtaken it for the first time.

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The Office of National Statistics has shown that dementia, including Alzheimer’s, now accounts for 61,686 deaths per year, or 11.6 percent of the total number of deaths in England and Wales. This shift is thought to be due both to an aging population and a greater awareness of the disease, which means it is now given more weight on death certificates.