I suggest you try to persuade grandma to take medicine and pay attention to her expression. You can do whatever you want. I mainly explain your grandmother's doubts for your reference:
1. "Taking medicine is a waste of money": If this is the main factor, consider switching to cheap antihypertensive drugs. Some antihypertensive drugs cost a few dollars a bottle (100 tablets).
2. "She ate her stomach again": Does she have stomach trouble? Why do you have this idea? Antihypertensive drugs are generally not available. (If yes, did you take aspirin, an anticoagulant). If so, you can consult a doctor for dressing change.
3. "Eat if you feel uncomfortable": As you said, it will fall off immediately after taking the medicine, and it will fall off quickly. Why is this? Let me give you an analogy: we compare the heart to a submersible pump and the blood vessels to water pipes. What happens when the submersible pump pinches one end of the water pipe when pumping water? The water pipe will swell, right? That is, the pressure of water on the water pipe increases-in the human body, correspondingly, if the blood vessels spasm, the pressure will increase, which is high blood pressure. The role of antihypertensive drugs is to relax vascular smooth muscle, which is equivalent to releasing the hand that pinches blood vessels, and the pressure will drop. So keep taking medicine, or your hands will tighten again.
Let's just say so much. Of course, persuasion must be combined with your grandmother's specific situation and personality characteristics, and then use what I said. Wish you success!