Why do some girls get copious periods and some get light?

[Anonymous]

And what difference does it make?

And is there any difference between them to begin with?

[ludorock]

It's just biology. Different bodies do different things.

What happens during a period is that the lining that has built up in a person's uterus throughout the month, to prepare the uterus to grow a fetus, sheds and comes out of the vagina as blood. (most other species reabsorb this lining, humans are pretty unique in how we operate in this area)

Some people have lighter periods because there's not as much lining, or gentler cramps because their body doesn't respond as strongly to the hormones that say "open the cervix, let the blood out!" so the cramping is lesser. Some people have regular periods, some are irregular, some are monthly, some are every other month or even more infrequent. And your periods are slightly different every month, and as you get older they also change.

[SaoirseS]

It's complicated, but heavy periods have a lot to do with hormone levels, some say even diet, which makes the uterine lining thicker and results in heavier periods. The difference is usually in the amount of tissue passed. In either case it's a good topic of discussion for a woman to have with her doctor at regular checkups. Periods that are too heavy and result in a lot of blood and tissue loss may be the sign of other problems, like fibroid tumors.

[Hangry06]

Each girl is different.

[Pterodon]

You’ll have to ask their uterus