Some sinus infections can be cured and go away on their own without the use of antibiotics if the sinus infection is not a bacterial sinus infection.
If the sinus infection is not a bacterial sinus infection then it will usually go away on it's own within 1 to 2 weeks but if the sinus infection seems to get worse or lasts longer than 2 weeks then it could be a bacterial sinus infection.
For a bacterial sinus infection it too can eventually go away on it's own without the use of antibiotics but it's best to get prescribed some antibiotics for the bacterial sinus infection to kill the bacteria and make the sinus infection go away much sooner.
After taking some antibiotics you should be feeling better within 3 to 4 days but the sinus infection may last longer without the use of antibiotics.
When you have a sinus infection it's a good idea to see a doctor anyway just to find out what type of sinus infection you have.
But you should also stay hydrated, get plenty of rest and add some humidity to your room through the use of a humidifier.
A steamy shower can also sometimes help with sinus infections.