Dear Dr. Roach: I am 89 and in good health. For six months, my systolic blood pressure was 113 mm Hg. Then, 10 days ago, it dropped to 88 mm Hg for a week. For today and the past week, it’s been 187 /93 mm Hg. I was on a blood pressure medication, but my doctor took me off of it when my blood pressure was low. I am currently off of all medications. What the heck is happening?!

— D.J.

Answer: Blood pressure levels go up and down all day and all night, but there are some common patterns to blood pressure changes. There is usually a surge in blood pressure during the first hours after awakening, and it usually dips at night.

Even beyond those general observations, blood pressure can change fromminute to minute, and thinking about something that makes us feel anxious or unpleasant can raise the blood pressure by 20% or more. So, if your average systolic blood pressure is 110 mm Hg, it would be expected to have occasional readings in the 90s or the 130s. It’s the average blood pressure that we are most concerned with. To get a good idea of the average, it’s best to get lots of blood pressure readings.

What I think is happening is that you had excellent control of your blood pressure and probably had a few low readings — either just due to chance, or maybe you weren’t drinking as much fluid (or taking in as much salt) as usual. It’s possible your doctor overreacted by stopping the medicine that your body really needed to control your blood pressure.

Some blood pressure medicines don’t last all day, so if your blood pressure was measured when the medicine was most effective, this might also explain why your pressure seemed to be lower that week.

The best way to sort this out is through taking multiple blood pressure readings every day with a home monitor. They aren’t too expensive, and you can find a validated device at ValidateBP.org and base the dosing of your medication on the average reading. For age 89, extremes in blood pressure — 88-187 mmHg, for example — aren’t ideal for your heart and brain.

Dear Dr. Roach: I have diverticulosis. I like and want to eat berries for a better diet, but I’m afraid that it’ll start an episode of pain. Is there an alternative besides supplements?

— S.T.

Answer: A healthy diet for diverticulosis is pretty much a healthy diet for most people. In my opinion, increasing fiber through diet is preferred over increasing fiber through supplements. Berries are a great choice because they are high in fiber, relatively low in simple sugars, and delicious.

You may be worried about the seeds found in berries. The common teaching has been to avoid these for fear of plugging the openings of diverticula. However, the consensus is that seeds, nuts and corn do not precipitate attacks of diverticulitis. However, if you’ve had problems with certain foods triggering an attack, it makes sense to avoid them.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.