Getting to know your breasts goes deeper than their external appearance. Doing breast self-exams at least four times a year is a good way to monitor changes in breast tissue that could indicate breast cancer.
According to Trubow, you should look for a pebble or a frozen pea-like lump. "It's often something that you can feel from all angles and that doesn't go away in one direction," she says. "It's usually a little more difficult and either mobile (moving), but it can also be fixed on the spot."
If you're someone with naturally lumpy breast tissue (also known as fibrocystic breasts) to differentiate this from something more worrisome, Trubow says that harmless lumps are generally felt from one direction but not felt from another.
"When you're menstruating, it's best to examine your breasts a few days after your period ends, when they're the least tender, lumpy, and bumpy," adds Gilberg-Lenz. "You will always know yourself best! If you feel or see anything else in the skin, nipple, under your arms / armpits, see your doctor."