5 month old having awful nightmares

[CyrilSneers]

I know there's probably nothing I can do about this, but my 5 month old is having the most hideous nightmares. This morning he was breathing so heavily and erratically and whimpering so badly that I thought he might be having some sort of fit! He wakes up absolutely howling and is really distressed
Anyone else experienced this in a baby so young? What the hell does a 20 week old have nightmares about?!

And according to google babies don't dream until they are 1??...

I doubt it's real nightmares, more likely trapped wind or something. Both mine used to do it, it's not pleasant to watch, I just used to stroke and shush them, or pick them up and cuddle them until they calmed.

Are you sure it's not night terrors? I had this with DD1 when I got obsessed with getting her into a routine and was restricting naps. All a result of over tiredness, as soon as I let her sleep more they stopped (and never came back).