Is there more than one symptom of 'jet lag' ?

Yes: Jet lag symptoms can include headache, mild nausea, and of course fatigue. Feeling "awake" and unable to sleep when you should (eg: in the middle of the night), also typical.

Jet lag: Jet lag symptoms: Fatigue or sleepiness, decreased concentration, moodiness, GI changes (diarrhea, nausea or constipation), headache, sense of not being well & sleep disturbance (insomnia or early morning waking). Hydrate really well wi water, before, during & after travel. Stretch during flight – whether you walk about or do it in seat. Start shifting meal & sleep time before your departure.