9 month old suddenly waking in the night

[SiTay]

Hi - so DS has slept through from 3 months old (with some off nights) and has self settled since 4 months old.
DS has started to wake in the night crying, the first night he cried when we left the room at bedtime but now he's back to self settling (touch wood). When it comes to about 3am or any time there after he wakes up making crying noises but no tears so me or DH go in, turn him to side and tap him to help him settle, it worked one night and last night he was awake for an hour and half and it ended up turning in to full blown tears. We tried nurofen, gripe water, ambosol and even our bed which made him worse, we eventually gave him a 5oz bottle.
Has anyone else experienced this or have any advice as I don't want to create bad habits or to be missing anything?x

[crazycatlady5]

Could be anything down to teething or separation anxiety, he could be frightened when waking and therefore seeking parental help to get back to sleep x

[Dancer123456]

There is usually a nap transition at 9-10 months from 3 naps to 2. It messes with their sleep cycles.

[SiTay]

@Dancer123456 he's been on two naps for a little while now. Do you think the sleep transition can affect him that much at night?x