Ive had BP issues for about 10 years before we got it under control. It is a silent killer. I had no appreciable early symptom package to speak of. EVerything I had could be considered autocorrelation and not part of the BP problem/ When BP is high and unchecked for many years , it is like a causitive thing that helps to make your blood vessels less pliable and your heart work harder (In between beats the heart is resting, and when the systolic/diastolic numbers are too close,(no matter how "low" you may think your BP is) your heart aint resting, its working through "its break time").
So, all the factors that become serious, atthrysclerosis, heart failure, kidney problems, strokes , etc are all a consequence of your vascular system being beaten witha sledge hammer and eroding your vascular and cardiac system after years of BP. Its lkike a piping system that gets no maintenance . Over time the negative effects of chemical erosion and physical breakdowns of the pipes just catch up . The big BP study that went on in Framingham MAss years ago let us understand how the interrelationships of caused ailments were related to BP and , if left untreated , what could happen.
The fact that there are usually no sympoms until its later in the game( like one poster talked about swollen feet--this usually only occures AFTER some damage to the heart has occured, Edema is a mid time symptom of initializing heart failure).
Most of the symptoms that people mentioned (with the exception of headaches which are an early disease symptom due to non dilating vessels in the skull surface), almost all symptoms dont start appearing until some damage has been done, otherwise they are just coincidental symptoms that have little to do with the underlying disease.
There are some newer studies that have taken off from Framingham. Theres a study on the benefits (or not) of a mediterranean diet on BP(LYONS diet), theres a study of ethnographic factors on BP by looking at several populations of Slavic, Irish, and AMerican Indian (I thinkthat this study is waaay too optimistic and has not considered all the variables so Im not holding out any positive net results).
These and many more studies are attempting to look at the relationships of early life anomalies and chronic e care for cardiac related symptomology (My favorite is the study on th relationhip of diabetes and cardiac stress).
Well, you asked, and any of us who are BP care patients have years of experience and some knowledge that we pump out of our medical mechanics .