President Donald Trump said Thursday that he plans to declare the opioid crisis a national emergency. Clearly, the massive increase in drug deaths warrant a serious government response. But what does a national emergency actually mean?

There are two avenues the president could use for a national emergency declaration. Under the 1988 Stafford Act , the president can get immediate aid to a community or region dealing with a crisis through the Federal Emergency Management Agency. FEMAs website makes clear that these declarations happen every couple of days and are mostly related to local issues: fires, storms, flooding, gas leaks, and pipeline breaks.

James Blumenstock, chief of health security for the Association of State and Territorial Health Offices, said a major effect of this kind of declaration is getting money from a FEMA-managed fund into communities right away, and making sure local governments get reimbursed for extraordinary expenses.

The other kind of emergency declaration is a public health emergency, which falls under the authority of the Department of Health and Human Services.

These happen much less frequently.