What does it mean if you have stretch marks?

they just showed up and i have no idea what they are! Anything to worry about???
nothing to worry about,

They occur when the skin is stretched, so that could be growing in height, gaining weight, losing weight.

They will usually naturally fade.
Stretch marks or striae, as they are called in dermatology, are a form of scarring on the skin with a silvery white hue. They are caused by tearing of the dermis, and over time can diminish but not disappear completely. Stretch marks are the result of the rapid stretching of the skin associated with rapid growth (common in puberty) or weight gain (e.g. pregnancy). Although the skin is fairly elastic, rapid stretching of the skin will leave permanent stretch marks.[1] Stretch marks are generally associated with pregnancy, obesity, and can develop during rapid muscle growth from regular exercise.
nope, you're probably just growing. or you could have lost weight after the skin being stretched..
either you have just had a baby or lost some serious weight