Help with Blood Pressure diagnosis

Hi I am a otherwise healthy 43 year old. I am not overweight, I dont drink or eat junk food to excess. I eat a lot of fruit and veg and run 3 miles 4 days a week and 5 miles 2 days a week. I have always been fine. I felt a bit light headed and short of breath last week. I went to my GP who took my BP as being 190/140 he thought I was taking a heart attack and packed me off to hospital. They monitored my BP constantly for 24 hours and the lowest level it fell to was 183/115. They have put me on BP tabs but my pressure today was still at 187/115. I feel a lot of pressure in my head. They are diagnosing secondary hypertension without saying what the primary cause might be. Can anyone help?
I should add that I am not stressed out I am normally very laid back.

[RedinLA]

190/140 is not good. DO YOU SMOKE? I noticed you did not list that. You do however exercise which is good. Low sodium, Do you drink coffee? NO CAFFEINE!!! Low protein. Sufficient rest, do not over sleep. Mild sedation from your doctor. Does your family have history of heart problems or high BP? These are all things that matter and should be looked at. Sorry that is all I can do for you. I also heard that if you have an aquarium,, they said to sit and watch the fish swimming, suppose to calm you. How about a spa day, relaxing

[caregiver222]

That is quite high and on the verge of life threatening. You neglect to mention the pulse rate. Without knowing that the blood pressure reading is not that helpful. A common cause is plaque build-up in the carotids, where the sensors are that regulate blood pressure. In the United States protocol would require, among other procedures, a dopplar of the left and right carotids. You mention you have been "short of breath". A high blood pressure may be compensatory, and result from chronic obstructive pulmonary disease, asthma, or a low hematocrit. What you need is a competent work-up.