STI questions

[AutumnDragon]

As the title suggests, I have a couple of questions regarding STIs

Will things like gonorrhoea or chlamydia get better if left i.e like other "infections" such as colds etc?

If not, some people don't get symptoms, so what about long term effects from not treating them?

If the male has one of the above, will he definitely pass it on to the female the first time they have sex after he is infected, or could they have intercourse a few times without her getting it?

Thank you!

[InsufficientlyCaffeinated]

If Chlamydia or Gonorrhoea are left untreated they can cause PID.
Don't know the answers to the others

[Imnotaslimjim]

Most STI's need treatment to get better

As caffeinated said, untreated they can lead to PID and infertility.

No, you won't definitely pass it on every time you have intercourse but obviously the more you have PIV with someone infected the higher the risk of contracting it is.