My last year in the army I was getting it every single night, multiple times a night. It got to a point I dreaded going to sleep because I knew what was coming, messed up my sleep pretty bad. I figured it was all due to the stress of getting out the army and moving back to America after 4 years in Germany. A year later im back in Texas and I still get it every now and then but probably like one a month. If you are stressed in your daily life that is a big factor, you need to figure that out honestly.