I’m 18 and I still don’t have any chest hair. I have body hair grow everywhere else except on my chest. Why? And should I be concerned?

Thanks for your question. Body hair, in sex-assigned at birth males, is mostly affected by genetics and androgens (which are hormones such as testosterone). If you have body hair in your axilla (or armpits) and pubic area, and you have gone through puberty, your hormones are probably normal. You may have less chest hair due to genetics. To be sure, you can always talk to your health care provider. They can ask you more questions, do a physical exam, and order any tests, if needed.
Here’s a tip on how to bring it up to your health care provider: “I don’t have chest hair. Is that okay?”​