You can easily get Chlamydia from someone who is infected if you have vaginal, anal or oral sex without using a condom. You can also get it if you share sex toys without washing them or without covering them with a condom each time before you use them.
As Chlamydia is found in semen or vaginal fluid, it’s even possible to pass it on from one person to another on your fingers.
If you are pregnant, you can pass Chlamydia to your baby while you are pregnant or as you give birth.