Your eardrums might explode and you'll get an ear infection. I can tell you that from my own experience.
Yes, you can die from holding in your sneeze, because your sneeze can go about 90 miles per hour and so if you do hold it in you can suffer from brain damage!
By holding a sneeze in, you can damage the blood vessels in your eyes, nose, and in your throat. You can also cause your eardrums to be damaged.
You can't sneeze your brain out
If you sneeze on a Tuesday, you will kiss a stranger. The whole rhyme goes: If you sneeze on Monday, you sneeze for danger; Sneeze on a Tuesday, kiss a stranger; Sneeze on a Wednesday, sneeze for a letter; Sneeze on a Thursday, something better; Sneeze on a Friday, sneeze for sorrow; Sneeze on a Saturday, see your sweetheart to-morrow.
It's much better to let yourself sneeze. You sneeze because there's something inside your nose that isn't supposed to be there. When you sneeze, the air blasts out whatever was bothering your nose. Also, the pressure from holding in a sneeze could hurt your ears.
jack shite
It's never been proved because closing your eyes is the natural reflex. However, there's an urban legend stating that if you sneeze with your eyes open, your eyes will be forced out of your head by the extreme force and speed of the sneeze (supposedly over a hundred miles an hour). Don't try this at home! Actually nothing happens when you sneeze with your eyes open. The spray is going outward when you sneeze and won't land on your face or eyes if you try holding your eyes open as you sneeze. Besides, this was tested on Mythbusters of the Discovery Channel when Adam Savage attempted to sneeze with his eyes open: his eyeballs didn't pop out of his head like the urban myth implied. The only thing that happened, especially when viewed on high-speed, was that he looked hilariously foolish sneezing with his eyes open!
Your whole head will explode
Holding in a sneeze is like holding down the top of a jack-in-the-box. Why not just let it out? The air expelled by sneezes is said to travel up to 100 miles per hour; holding in a sneeze could cause fractures in the nasal cartilage, nosebleeds, burst eardrums, hearing loss, vertigo or detached retinas. Therefore it is best to let your sneeze fly (yet shielded by a hankie, preferably). Plus, your body is trying to clear out your pharynx-and that's a good thing. To help the sneeze come out, look at a bright light. This stimulates the optic nerve, which crosses wires with the sneeze center. The added irritation of an adjacent nerve will get the sneeze going.
You sometimes get a tissue and blow your nose.
You turn into a cactus
yes, you lose 10 brain cells