I saw 19yo DS without his shirt for the first time in ages today

[WoodenClock]

He's generally very secretive about his body, to the extent that I have occasionally worried that he's self harming. I don't think he is, but he does keep well covered.

Today he's had an accident on his bike and has let me look at his injuries. He's got some nasty grazes along his side.

However, I also noticed dark horizontal lines on his back. He says they've been there for ages and don't hurt. I'd guess probably stretch marks, but they're solid lines, they don't have that feathering I'd usually associate with stretch marks.

Is there anything else they could be. I.e. should I be worried?!

Hard to say Wo a photo tbh.

But my ds has some on his lower back. They are purple ish and horizontal. Are you ds the same?

Very normal, I thought my DH had been whipped when I first saw him shirtless. They do fade a bit in time. Do they look like zebra stripes on the sides of his back?

If you google something like stretch marks back boys you will see many examples.

My husband has huge stretch marks from teenagerness and they look nothing like mine. Some of them are probably a thumb width thick and still dark and in a solid horizontal line.

Yes, probably stretch marks.

Boys can grow pretty quickly, hence the stretch marks

My son has a lot on his lower back area - don't seem to bother him too much.

My son has horizontal red lines on the base of his back too. He's 15 and grown a lot in the last 2 years

I saw my 14 year old’s back recently and was shocked to see large stretch marks on his lower back. Then looked at his twin brother’s back and it was exactly the same! After looking on google it is really common with such rapid growth. It doesn’t bother them.