What's wrong with my hedgehog?

It sounds like pneumonia probably resulting as a secondary infection caused by a lungworm infection. A vet will probably be able to treat the condition - especially if you provide a copy of the following to aid diagnosis:

I quote the following: . “… LUNGWORM. Very sadly, this accounts for a huge mortality rate, every year - in some areas, it’s been reported up to about 80% of the population! This is a very nasty disease that if not treated, will result in death; if the infection is very bad, the lungworms cause a lot of damage to the lungs, severe mucus production and weight-loss, because badly infected hedgehogs refuse to eat - and therefore need to be liquid-fed using a syringe. When we receive infected hedgehogs/hoglets, (they are kept isolated), we see symptoms including green or mucus droppings, snuffling, coughing, bubbles from the nose and wobbles. The coughing seems to mostly occur when the hedgehog is sleepy or asleep - it is vitally important that each infected hedgehog is able to cough up the dead worms. Bubbles from the nose indicates the start of pneumonia (a secondary illness), caused by the mucus/fluid in the lungs. We sometimes receive whole families that are ALL infected - because this disease is highly infectious! Infected hedgehogs are given worming injections by the vets, antibiotics and a course of wormer to be given orally. Treatment is designed to kill the worms, but they still need to be coughed up.
…”

From “ Spikey’s Hedgehog Rescue “ at . http://funadvice.com/r/14sgp7csi1g . Sorry I can’t suggest anything less serious. .

– Best wishes - Majikthise. .

He sounds like he has a hedgehog cold (if that’s possible). Maybe you should take him to the vet, just to be sure he will be okay(: Goodluck with Mr. Hedgey.