system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 what is the difference between a headache and a migraine?
gpt
A migraine is a very specific type of headache, often identified by the symptoms "POUND";
P: Pulsating
O: onset of several hours
U : unilateral
N: nausea
D: debilitating 
Many people get extremely sensitive to lights and sounds and need to stay in dark rooms until the migraine goes away. Some people get changes in their vision called auras before the migraine begins. 

There are several other headache types including "tension headaches" (the most common, often called stress headaches).