From research over the last 30 years it is evident that blood pressure-lowering
drugs are effective in preventing strokes, heart failure and kidney failure due to high
blood pressure. In the small proportion of patients with very high pressures and
symptoms of headache, blurring of vision and breathlessness, treatment produces
rapid relief of symptoms. However, it should be emphasised that benefit has also
been shown in patients with no symptoms and moderately raised pressures. Because
the risks of blood pressure are grater when levels are very high, the potential benefits
of treatment are greater in these patients. It is still a matter of intense debate and
research how high blood pressure has to be before there are realistic benefits of
treatment in patients with borderline hypertension.