Persons most commonly affected: All ages and both sexes, but most common in children and older people.

Organ or part of body involved: Nose

Symptoms and indications: Sudden bleeding usually from one nostril only. Blood can be either dark or bright in colour.

Causes and risk factors: By an injury to the nose, breathing dry air for prolonged periods of time, repeated blowing or picking of the nose, tumors in the nose, hypertension and certain diseases of the blood.

Prevention: You can help to prevent nosebleeds by: Not picking your nose; Being gentle whenever you blow your nose; Not smoking; Using a humidifier if your indoor climate is dry during the winter months; Using a nonprescription saline nasal spray to moisturize the inside of your nose; Applying a dab of petroleum jelly to the inside of your nostrils before bedtime; Avoiding facial trauma by wearing a seatbelt and shoulder harness in the car and by using well-fitting headgear to protect your face during contact sports, such as football or karate; and Using protective equipment to avoid breathing irritating chemicals at work. If you are bleeding from the front of your nose, begin by trying the following first-aid measures: Sit up (so your head is above the level of your heart), lean forward slightly and breathe through your mouth. With your thumb and index finger, pinch the entire front of your nose (just above your nostrils) and hold for five minutes. At the same time, use your other hand to apply an ice pack or a plastic bag of crushed ice to the bridge of your nose to slow blood flow. After you have pinched your nose for five minutes, release it to see if your nose is still bleeding. Keep the ice pack on for another 10 to 15 minutes. If your nose is still bleeding, pinch it for an additional 10 minutes. Release your nose again. If you are still bleeding, seek emergency medical help.