Hi,
After going through your question there might be following possibilities for relative decrease in blood pressure in your case-
1) Heart problem post-prandial angina (pain after dinner).
2) Normal- effect of
anti-hypertensive medication.
3) Other illness like febrile illness,
dehydration.
I want to know-
1) Your age, gender.
2) Height and weight.
3) past Medical history like presence of diabetes, blood pressure,
cholesterol problem,
heart disease.
4) Family history of heart disease.
5) Habits like smoking.
6) Associated symptoms like vomiting, loose motions, fever.
You should visit your doctor and get done clinical examination.
Following investigations are important in making diagnosis, decision making.
1) ECG
2) Cardiac enzymes like Trop T/I, CPK-MB.
3) 2DEcho of heart.
4)
Ultrasound of abdomen.
Till that time use antacids.
Hope you will find it helpful, if so do vote.