Occasional insomnia with frequent urination and rapid heart

I have searched the internet for this problem which I have as I can't find the cause of it. It is more common on nights when I don't drink alcohol. Basically, I feel normally tired and as if I am ready to sleep but my heart will be a bit racy followed by the frequent need to get up to urinate. Like my bladder is hyperstimulated. This goes on for hours and prevents me from sleeping. It happens around once a week. I have to get up by 6.30 am and so if I am still lying awake at 2 am I take a sleeping pill. But I am nearly out of sleeping pills and the doctor will not prescribe any more.

Anyone else get this? Any ideas on what causes it?

at a guess, I would say one those nights you are doing something different in the several hours before sleeping that is causing a surge in adrenalin in your body.  this could explain both the raise in heart rate but also need to urinate. 

It could be as simple as some stressful event that day (or even intense TV programme), or it could be a minor allergic reaction to a food or drink you tend to have once a week. 

you might really benefit from a deep relaxation exercise every night or brainwave entrainment recordings.  have a look at www activemindsglobal com 

Many thanks Scottie. I had wondered if it was something I'd eaten as often when it has happened I have had something high in sugar, or something such as cranberry juice. But on the odd occasion it happens, I haven't. Thanks for the link, I'll take a look.

Bumping this as I'm still suffering from this infuriating insomnia. The only thing that workss is to take a temazepam but I don't have many and the docs are so resistent to prescribing them now. I have to sleep as I need to drive late at night to pick my son up from his job, so can't be too tired.