Nosebleeds can be caused by a number of different things. It's not always possible to identify the exact reason why one occurs. Nosebleeds can start just inside your nostrils (anterior) or at the back of your nose (posterior). These different types of nosebleeds tend to have different causes.

Anterior nosebleeds
The vast majority of nosebleeds are anterior nosebleeds, which means the bleeding comes from the wall between the two nose channels (the lower septum), just inside your nose. This part of the nose, known as Little's area, contains many delicate blood vessels that can be easily damaged.

Posterior nosebleeds
A small number of nosebleeds are posterior nosebleeds, which means the bleeding originates from branches of arteries that supply blood to the space inside your nose between the roof of your mouth and your brain (nasal cavity). These nosebleeds are more common in adults than children. They can be more serious than anterior nosebleeds and bleed more heavily. Medical attention may be required.

A nosebleed can be stopped simply and effectively by soaking a plug of gauze or cottonwool in cold water (iced if possible) with a drop or two of essential oil of Lemon, and inserting this as far up the nostril as possible. Oil of Lemon is a haemostatic (i.e. it stops bleeding by speeding up the rate at which blood forms clots).

Get the victim to lie down in a quiet place, and put an icy-cold compress at the back of the neck - maybe with a few drops of oil of Lavender added. If the bleeding continues, get more qualified help, as the amount of blood lost can be serious.

Most nosebleeds result from minor injuries, but they may also be a symptom of high blood pressure or other serious disorders, so anybody who has nosebleeds frequently needs more than the first-aid help described here, and the cause of the bleeding must be sought and treated.