Bulging discs and especially herniated discs in the spine can be a source of pain. Discs made of cartilage cushion the bones in your spine; when a disc bulges, it sticks out of the space it’s supposed to occupy. Bulging occurs with age and often does not cause pain. Herniated discs — also called ruptured or slipped discs — occur when the tougher outer layer of cartilage on a disc fractures enough to let some of the soft insides push out. They are more likely to cause pain.