Question

My father keeps having dizzy spells. They seem to occur when he stands up and when he has been eating but his doctor can find nothing wrong. What might cause these?

Answer

There are a number of possible causes of your father's dizziness. Orthostatic hypotension means that the blood pressure falls with changes in posture and with walking. In some cases this can be a side effect of certain medications. This change could be excluded or proved by taking your father's blood pressure lying down, and then standing after 2 minutes. If it remains the same, he should walk a small distance and then take his blood pressure again. You can do this yourself if you have a blood pressure monitor. If there is no change in blood pressure, or if it goes up from lying to standing to walking, he does not have orthostatic hypotension. If he does have orthostatic hypotension, he might ask his doctor to review his medications to see if they are the cause.

Your mention of the association with food could be very relevant. Light headedness and dizziness can be associated with a low blood sugar in certain people. This occurs after a meal and results from an excess output of insulin. It can be controlled by eating smaller, more frequent meals. There are other people who suffer from what is called post-prandial hypotension, that is a drop in blood pressure after a meal, and once again it would be possible for your father to measure his blood pressure before and after a meal to see whether this occurs. If it does, then strangely enough he may well find that a cup of coffee after his meal (the coffee must contain caffeine) might well help him to reduce the symptoms.

If, on examination, the dizziness is not caused by orthostatic hypotension or the effects of eating, then perhaps your father should go back to his doctor for further tests.

The more persistent dizziness that your father finds when he lies down may well be due to poor circulation to the balance part of the brain. In this case he may well benefit from medication such as aspirin to stop micro-emboli forming.