Hbp rises due to eating a diet
full of salt and water. People with hbp have difficulty excreting excess salt and water. If a person with hbp eats a diet filled with salt (hamburgers or steaks) and fluids (excessive coke or beer), then they will see a spike in their blood pressure
because they can't get ride of this extra salt and fluid normally.
Not taking your meds will lead BP spikes as well.