My girlfriend woke up in the middle of the night feeling jittery and hot. She went outside and sat in the cold air and drank water. When she came back in she said she still felt jittery and "strange". She did not have a fever. And she has not drunk coffee today. She says her stomach feels heavy like she is 9 months pregnant.(she is not pregnant). She is 30 years old. She is not on medication. She is sleeping now but said she didn't feel sick but rather "strange" jittery and hot.
Are these things a common sign for something specific?