Low blood pressure in the middle of the day in the elderly may be related to taking antihypertensive drugs, physiological factors, and postprandial blood pressure changes. 1. Taking antihypertensive drugs: Older people suffering from hypertension need to take antihypertensive drugs for long-term treatment. Most of the old people take antihypertensive drugs in the morning, it takes about 4~5 hours to reach the peak of blood concentration after taking them, so they are at the peak of blood concentration at noon, and low blood pressure may occur at this time. 2. Physiological factors: usually normal blood pressure fluctuates during the day and at night, most people’s blood pressure is at its peak at 6-10 am and 4-8 pm, and gradually decreases at noon, that is, after 10 o’clock, so low blood pressure at noon is a normal physiological phenomenon in the elderly. 3. Post-meal blood pressure changes: In daily life, most people may also experience low blood pressure after eating at noon. This is usually due to the fact that the blood in the body will be distributed in the gastrointestinal tract after the meal to promote the digestion and absorption of food, resulting in a reduction of blood in the peripheral blood vessels, thus causing low blood pressure. When elderly people have low blood pressure in the middle of the day for a long period of time, it is recommended that they consult a doctor in time to determine the cause of the problem and then treat it.