If you've been following the news for the past couple of weeks you've no doubt seen lots of hand wringing about North Korea's missile tests. To summarize, they've popped off a couple of missiles that seem to have intercontinental capability, i.e., they could, in theory travel from North Korea to the vicinity of the United States or Canada and deliver their payload. The missiles in question keep landing in the ocean, which strongly suggests deliberate targeting to prove launch and control capability as well as making it more difficult for other countries to get hold of the hardware for analysis. That payload, of course, is what has many worried. Additionally, it's been observed that the US military's anti-ballistic missile capability is less than stellar. Official word from the Pentagon is that they're confident that they could handle such a problem, some evidence backs that up, and other evidence casts doubt upon them, such as failing 75% of the time. Coupled with North Korea kicking up propwash in the international media about US and South Korean forces training together about cutting loose if the two countries don't knock it off (spoiler alert: they haven't and aren't).
On the other hand, earlier this year North Korea successfully put a satellite into orbit (even though it's tumbling, which makes it useless for anything other than a proof-of-concept) and detonated a bomb powerful enough to register as a seismic event several thousand miles away. Regardless of what one may think these are not events to dismiss lightly because they demonstrate dual-use technical capability; the rocket booster used to put the satellite into orbit could also be used to propel a military payload into the airspace of another country, and even if the bomb detonated on 6 January 2016 wasn't actually a hydrogen bomb, it was certainly powerful enough to level a city.
That said, here's my two cents: Sit down, have another cup of coffee, and find something interesting to do.
No, really. Don't worry about this.