I’m 21 and have just discovered a small lump in my left breast. This has terrified me.

Do you think it could be cancer?

At age 21, it’s very unlikely you have breast cancer. Nevertheless, any lump in this part of the body MUST be checked out by a doctor, as soon as possible. The majority of breast swellings turn out to be benign, ie non-cancerous. The most common ones are cysts, which are collections of fluid, and fibro-adenomas which, as the name suggests, are fibrous swellings.