DEAR DR. ROACH: Why do older people tend to get lightheaded (not vertigo) and therefore become liable to trip or fall? What causes that, and can anything be done? I’m an 83-year-old lady afraid to trip over the garden hose or her own feet. — A.R.
ANSWER: I’m glad you made a distinction between lightheadedness and vertigo. Vertigo is a sensation of movement when there isn’t one. Most commonly, it’s a sensation that the world is spinning, but sometimes the person is spinning, or the movement can be up and down, or side to side.
Lightheadedness, by contrast, is a different feeling, often described by people as though they are going to pass out, which can sometimes happen if a person doesn’t sit down quickly.
Lightheadedness can happen to people at any age, and although it happens to plenty of adolescents, it is much more common in older people. One of the main reasons for lightheadedness on standing is a relative lack of blood flow to the brain. The body has powerful mechanisms to maintain blood flow despite the dramatic shift in the pressures required to send blood against the pull of gravity, as well as to keep blood from pooling down in the legs. These reflexes are a little slower in older people. I advise people to change position slowly to give the body time to adapt. From lying down, move to a sitting position for a few seconds or a minute before standing up. Once standing, make sure you are steady before walking.
If you feel lightheaded all the time, not just when you change positions, you should discuss this with your doctor. You didn’t mention medications, which is one of the most common causes of this problem. Since at least half of older people are taking medications that can affect blood flow and blood pressure, medications are a frequent culprit, but obviously need evaluation before they are adjusted.
There can be many other causes, including heart problems, so this is definitely something to get evaluated if it has not responded to these simple recommendations.
DEAR DR. ROACH: I always have a more serious reaction to vaccines than my husband. This is true for both COVID-19 and others. Could it be because I weigh only 125 pounds versus his 220 pounds? Why don’t they administer the vaccine amount based on one’s size and weight? — S.V.
ANSWER: While any given person may be more likely to have a vaccine reaction than another, it is generally true that women are more likely to have symptomatic reactions to the COVID vaccine than men. Almost 80% of reported adverse effects from the vaccine came from women, according to a recent Centers for Disease Control and Prevention study. Just over 60% of vaccine recipients are women. This is consistent with previous studies looking at side effects from other vaccines, such as the flu shot.
It’s not clear why. It is clear that women tend to have a more robust immune response, generating far more antibodies than men, and that may be reflected by a greater symptomatic immune response. Fortunately, the side effects are for the most part short-lived, and both men and women have a high degree of protection.
Men have more muscle and bone tissue than women, but the size differences in the amount of blood and of the lymphatic tissue responsive to the vaccine between the sexes are small. Vaccine doses for adults generally do not need adjustment for weight.
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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.