@gollum,
Hi! Do not presume that your blood pressure issue is because of increased sodium level before consulting with doctor. There are many other reasons like -
1. Increased weight
2. Lack of physical exercise
3. Some hormonal dis balance
4. Hyper tension
5. Stress
6. Consumption of alcohol
And many other factors are their that causes high blood pressure.
So, before taking any medication consult your doctor.