Ask the Doctor

Nosebleeds are usually nothing to worry about, but let me put your mind at rest by explaining what goes on when you have one. Nosebleeds can be caused by allergies or infections from heavy colds

The lining of the nose has a rich blood supply, which helps it warm, filter and humidify the air you breathe. The problem is that this lining is also very delicate and is easily damaged by irritants in the air and wandering fingers.

Infections such as heavy colds and sinusitis and allergies can also make you prone to nosebleeds. That’s because they inflame the nasal lining, increasing blood flow and in turn making the lining more fragile.

When you blow your nose, the pressure causes the tiny blood vessels (capillaries) in the lining to rupture – and because there is such a good blood supply to the area, you get lots of blood.

The usual advice to stop a nose bleed is to pinch your nose about half an inch up from the tip – this is known as the Little’s Area and is the source of most nosebleeds. It’s where several large arteries meet, and it’s also a site that dries out easily as air hits it when it enters the nose, making the lining particularly fragile.

But if you pinch your nose for 10 minutes and it keeps bleeding, it’s likely the bleed is coming from farther back. In that case, treatment by an expert is needed and usually involves packing the nose with gauze to put pressure on the bleeding vessel to allow a clot to form.

If the bleeding is always from one side, there might well be a vulnerable bleeding point which never fully heals. It might be worth having this cauterised (burned and sealed) under local anaesthetic.