In Japan, a nosebleed is considered a sign of sexual arousal. In the UK, it's considered a pain in the behind.
But what causes them?
Your nose is filled with lots of blood vessels with only a thin membrane to support them - the bleeding occurs when this faces a minor injury.
There are two types of nosebleeds - anterior and posterior. Anterior nosebleeds come from the wall between the two nose channels (the lower septum), just inside your nose.
Kids get these a lot. Hint: they are often caused by picking your nose.
Posterior nosebleeds take place further back and higher up in the nose where arteries are. Sometimes they can be severe enough to warrant going to hospital. A bump or a punch may trigger one of these, but also cold, high altitude and dry air.
Anything that dries out the nose makes it more prone to a nosebleed. Spontaneous nose bleeds can indicate hypertension or infectious disease, vitamin C deficiency, anaemia or heart failure.
So, how do you stop one when it's mid-flow?
"You can usually stop a nosebleed yourself by pinching your nose just above your nostrils for 10 minutes. Leaning forward and breathing through your mouth will drain blood down your nose instead of down the back of your throat," says the NHS.
After the nosebleed has stopped, it can be tempting to pick off the scab, but experts advise against it.
"After having a nosebleed, a "crust" will form inside your nose. This may be unpleasant, but try not to remove it as it is part of the healing process and will help prevent nosebleeds from re-occurring."