The most common cause of nosebleeds is dry air. Dry air can be caused by hot, low-humidity climates or heated indoor air. Both environments cause the nasal membrane (the delicate tissue inside your nose) to dry out and become crusty or cracked and more likely to bleed when rubbed or picked or when blowing your nose.

Why did I just randomly have a nosebleed?

Two of the most common causes of nosebleeds are dryness (often caused by indoor heat in the winter) and nose picking. These 2 things work together — nose picking occurs more often when mucus in the nose is dry and crusty. Colds also can cause nosebleeds.

Should I be worried about a random nose bleed?

Most nosebleeds aren't serious and will stop on their own or by following self-care steps. Seek emergency medical care if nosebleeds: Follow an injury, such as a car accident. Involve a greater than expected amount of blood.