PsychCentral posted this interesting paper recently...about the sensation of throbbing:

http://psychcentral.com/news/2013/08...lse/58683.html

I tend to wake up around 3 am sometimes, especially if I get to bed too early.

You can try melatonin at night. That might help.
If you get up in the night to use the bathroom, turning on a light is not a good idea. There are melatonin receptors in the retinas, and exposing them to light, turns off your own melatonin, and
then you can't sleep.

We have small night lights, along the floor baseboards that sense motion/or darkness and turn on, so that light in the eyes is minimal. We have a small nightlight in the bathroom.

I also found that antihistamines at night were making me throb sometimes, so I stopped them and it seems to be better. For some reason my hands/fingertips throb some nights.

I do think that as we age our brains change some, and sleeping becomes more difficult.