A lot of things you encounter online have been stripped of context. This could be due to inaccurate or misleading re-reporting, edited sound and video, images being shared with inaccurate captions, etc.

In some cases, stories or claims can get better as they pass through intermediaries. However, in most cases the more a story circulates, the more it becomes warped and you’re presented with a radically wrong version of an event or piece of research. This is when you investigate further and start tracing back to the original source for full context. 

Here is a video (1:34) on finding the original source. 

Here is a video (4:14) on finding original images and verifying caption claims. 

Here is an example of how you could approach tracing a claim. Below is a tweet you might encounter while scrolling through your feed.

This tweet is John's takeaway from the article. However, the article doesn't say to ditch your sunscreen. And it doesn't even say that the FDA is warning people about the chemicals. The study merely concluded that given the levels of the chemicals in the bloodstream — from applying sunscreen four times a day — that additional regulation might be warranted. 

This article isn't from a reliable source, and is in fact pulling all its quotes from another article. It's reporting on reporting. If you click through to the link (supposedly to the research article) it links to a CNN story. And in that story you notice the re-reporters left something out:

The original story actually says the opposite of what the tweeter proposed.

Tweeted Article: FDA Warns Chemicals From Sunscreen Enter Your Bloodstream After One Day

CNN Article: Sunscreen enters bloodstream after just one day of use, study says