I agree with animilo, it does sound like night terrors. They aren't all that uncommon in young children. You may wish to discuss this with your pediatrician, but I would also suggest you get the book, "Solving Your Child's Sleep Problems". My son's pediatrician recommended it to me when I was having similar problems. Very helpful info in it. Good luck!
what do you mean by "every night"? every night for the last two nights or every night for the last two years? The longer the duration, the more of a problem you may have. My son just turned two on the 2nd and very rarely will he wake up crying and even when he does, its no more than three minutes. LucyNJersey has a point on teething, but if not I would recommend seeing the doc....
It is night terrors and my son went through this. Since that age child does not sleep restless like an adult might, their brain goes into the same pattern of sleep each night. When the child gets to that stage of sleep, something goes "wrong" during one of the many dream states. It is usually in the deepest sleep/dream state in which this happens. His brain is still learning to wire itself. He is NOT AWAKE when he is screaming. He is still asleep , however he is acting out his terror with his body. Soon, the mind and body will work together and these sill go away. We left a hallway light on, or choose any type of light, and out a box fan in his room. We set it on low (or medium if you wish) and this made some strong "white noise". For some reason, that noise was able to keep him lulled asleep during the phase in sleep he was waking up in. See rest in comments.
Might sound funny but my nephew did that every night he stayed up a little late... It seemed if he was overtired, he would wake up screaming, crying and not easy to comfort around that time, but still in a very sleepy almost not awake state... We just made sure he was in bed at his usual bedtime (altho not always possible) and it seemed to go away for the most part, still tho at 8 years old it happens when he has a late night.
Your child may be having the same reoccurring nightmare. This doesn't sound good at all. If your child sleeps alone, try having him sleep in bed with you to see if it changes things. Or sleep in his room with him to see what's going on. Ask him what does he see or what's going on in his dreams that are scaring him. Sometimes demon spirits taunt children when they're all alone.
My son has this issue as well. Runs in the family. I was told he needs more sleep then others. He has no caffine and is in bed before eight. If I keep him on a routine, night light, and fan he has no issues. I would recommend seeing your doctor. He started about age two. Some nights were worse then others. That was until I started making sure he went to bed early. I made a journal until I found what worked best for him. Hope this helped and good luck! :)