Uffda,
Postprandial hypotension is characterized by a drop in blood pressure after meals. Normally the intestines require a large amount of blood to help with digestion. When blood flows to the intestines after a meal, the heart rate increases and the rest of the blood blood vessels in the body tighten down to maintain blood pressure. However, in some, such mechanisms may be not be enough to compensate and as a result blood pressure decreases.
Certain disorders, especially those that can effect the autonomic nervous system can cause the condition, it is also more pronouced in those with hypertension. In some the drops in blood pressure are severe enough to cause blackouts.
There is no magical remedy and the most effective treatments tend to be behavioral such as avoiding taking blood pressure medicine before meals and lying down or walking after meals. Also, smaller
meals and low carb meals may help.
Some say caffein or NSAIDS may also help, but this is debateable. You should probably be evaluated by a good internist for other conditions such as diabetes or cerebrovascular disease that can contribute or cause symptoms. Usually a good history and physical and limited testing can rule out any of these causes.
My definition of marked would be severe symptoms associated with the blood pressure drop, but I do not know if there is a true definition.
good luck
CORRECTION: Oops! My last paragraph above should read:
I