I am a 59 year old male in fairly good health. Suddenly I have not been able to ejackulate is there a natural cause for this situation.

Do you mean you reach orgasm but do not ejaculate or not able to reach orgasm?

Not able to reach orgasm

Are you under a lot of stress.
Have you recently started new medication.
Do you have a new sex partner

I am under a great deal of stress. The meds I am on I have been on with no problems before this. It is not a new partner.

Stress can do it, And to be honest at 59 sometimes due to the medication ( that latter was not hurting) it starts not working
** been there and done that myself**

Have you discussed this with your doctor

Thanks, the next step is the doctor

I agree with the stress factor. I have gone for extended periods without and looking back on it I see it was the stress.