I've had insomnia for the past few weeks. i can fall asleep but wake up 3 or 4 times a night. any advice?

What is the cause?: See doctor. Is insomnia new or did you have it before a few weeks ago? Doctor needs to look into possible physical causes first [for example, apnea? Other disease? Other medications? Drug abuse?]. Then, consider psychiatric causes [e.g., depression/anxiety, bipolar, other]. Finally, if appropriate, sleep medicine can help: ambien, lunesta, (eszopiclone) trazodone, doxepin, others.

Periodic limb move: Periodic limb movement disorder is characterized by occasional difficulty getting to sleep because of inability to get comfortable - and more importantly non-restorative sleep due to sleep disruptions from periodic tossing, turning, jerking, or kicking. A bedmate would confirm this as could the am sheets a mess.There are specific medications for this condition. Remember the goal is restful sleep.

Cause?: Important to know the cause: any recent issue in life that causes this? Too much caffeine? Do you get up to go to bathroom? I would see a sleep doc to get a full evaluation.

Reduce stress: Generally insomnia that is new and short term is related to stressors at home or at work. Try and identify stress you can reduce in your life and use good sleep hygiene. Sleep medications may be helpful short term to allow a good night of sleep.