system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do your eyelids get puffed up when you cry a lot?
gpt
You have little sacs on your eyes called a “lacrimal sac” that store and create tears 24/7 and it pushes out those tears constantly to your eyes so when you blink you are preventing your eyes from drying out. 

When you cry, you are suddenly making more tears than normal but they aren’t normal tears either, because it’s so much in such short of a time there is less salt in the tears. 

There is a saying in healthcare “where salt goes, water follows;” meaning that because those new tears don’t have enough salt, they will flood into the cells surrounding your eyelids due to the salt inside them. Which makes them puff up giving you that classic look. Additionally your lacrimal sac and ducts become overloaded causing tears to spill down your face. 


Sorry for the crap mobile formatting.