All the best. They can indicate a problem though. My piggie Khloe started sneezing a while back and developed a crusty runny nose. She had an upper respiratory infection which, left untreated, is deadly to pigs. I think its just dust from her bedding.
Weight loss is one of the first signs of illness in guinea pigs.
Its an instinct for them to hide sickness in the wild to avoid being picked off by predators, so often people never know they are sick until they show major signs. If your pig does have a respiratory infection you will notice it clicking when it breathes and it will appear to 'pant' or breathe heavily. It will need medication if this is the case. A good med is Chloromphenicol. Excessive sneezing is not usually normal.