Why do I have stretch marks?

Anonymous
Usually you get stretch marks because you either got bigger in size, are pregnant, or have the genetics for it. I have none of those. I'm not super skinny, but I'm nowhere near overweight. No person in my family has stretch marks (except for the women who have had kids). And I'm definitely not pregnant! Why do I have the ridiculous jagged purple lines on my inner thighs and white stretch marks on my sides? The purple marks on my thighs are ugly and make me think something is wrong with me. I don't know why I have them! My mother thinks something is wrong with me because she saw them when I was sitting in athletic shorts. She says no one my age or size should have them. They aren't just at the top of the insides of my thighs, they go down about four to five inches. They make me feel self conscious and unhealthy. It makes me ashamed of my legs when they aren't even big.
Updates
+1 y
I'm very physically active, so I'm not just sitting on my butt doing nothing about them. And I didn't grow fast. I grew very gradually.
Why do I have stretch marks?
5 Opinion