Diabetes Archive

On call

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Q. I've noticed recently that I sweat excessively, regardless of the temperature. Should I be concerned?

A. Your genes can determine whether you sweat a lot, but a sudden change in your regular sweating may suggest an underlying condition. Sweating is regulated by your nervous system and can be triggered by a number of causes. The primary signal for perspiration originates in the brain in response to a temperature-related or emotional cue, and then is carried by the autonomic nervous system to the sweat glands in the skin.

A Harvard Medical School doctor answers a common eyesight question

Q: Recently, I started to notice tiny threadlike shapes in my field of vision. My doctor says they are "floaters." Should I be concerned?

A: "Floaters" is a catchall term for what look like dots, threads, or cobwebs drifting across your line of vision.

Ask the doctor

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Q. Several years ago you wrote about a new technology called CRISPR that might make it possible to cure some incurable diseases. I keep hearing about this in the news. Is it any closer to reality?

A. Yes, there has been progress. What does CRISPR stand for? You don't want to know. What does it do? You do want to know, because it's pretty amazing. A colleague here at Harvard Medical School, Dr. George Church, says CRISPR enables a scientist to "edit any piece of any DNA a thousand times more easily and precisely than before, which is game-changing for gene therapies." Why would doctors and scientists want to "edit" DNA? Because disease is caused by genes that are not built properly or are not turned on and off properly. Both problems, theoretically, can be corrected by precisely editing the DNA that makes up those genes.

If you have a hacking cough and breathlessness, don't chalk it up to aging.

Maybe you never smoked, or you stopped decades ago. But you may still be at risk for chronic obstructive pulmonary disease (COPD). That's the umbrella term for a number of lung diseases that sometimes lead to disability and even death. "While about 80% of COPD cases are related to having smoked, 20% are not," says Dr. Bartolome Celli, a pulmonologist with Harvard-affiliated Brigham and Women's Hospital.

Diseases and symptoms

COPD includes emphysema, chronic bronchitis, severe asthma, or a combination of these conditions. They cause inflammation, destruction, or abnormal repair of airways and lung tissue, which reduces airflow and ultimately makes it harder to take in enough oxygen to supply the body.

A rapid heartbeat can be frightening, but this often-fleeting problem is usually harmless.

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If you're exercising or feeling very nervous, you expect your heart to beat faster than normal. But what if your heart sometimes starts racing out of the blue, for no apparent reason? You might have supraventricular tachycardia, or SVT. SVT is an umbrella term that covers several different types of rapid heart rhythms, all of which are caused by an electrical glitch in the upper part of the heart.

The most common SVTs are atrial fibrillation — a rapid, chaotic rhythm that increases the chance of having a stroke—and atrial flutter, a fast but usually regular heartbeat. But when cardiologists talk about SVT, they're usually referring to three different, less-common conditions (see "What is supraventricular tachycardia?").

Mounting evidence suggests that eating nuts and seeds daily can lower your risk of diabetes and heart disease and may even lengthen your life.

If your idea of healthy eating was formed a few decades ago, it may be hard to shake the notion that you should avoid nuts, which are high in calories and fat. But new evidence has overturned that assumption. In fact, a recent analysis of the nation's eating habits and health outcomes suggests that eating too few nuts and seeds is associated with an increased risk of dying from cardiovascular disease or diabetes.

For that study, in the March 7, 2017, Journal of the American Medical Association, researchers from the Tufts Friedman School of Nutrition Science and Policy relied on a model that used data from scores of observational studies on diet and health, including the National Health and Nutrition Examination Surveys, which provided detailed information on Americans' eating habits over the decade ending in 2012. They estimated that in 2012, over 300,000 deaths from heart disease, stroke, or type 2 diabetes — about 45% of all deaths from those conditions — were associated with eating either too much or too little of 10 nutrients.

Millions have prediabetes and don't know it. Here is why it's important to find out and act to lower your diabetes risk.

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An estimated one out of three American adults is prediabetic, which means blood sugar levels are higher than normal but below the threshold for type 2 diabetes. Yet 90% of these people do not realize they are in this dangerous gray zone.

"You are not going to have symptoms for prediabetes," says Dr. David Nathan, director of the Harvard-affiliated Massachusetts General Hospital Diabetes Center. "Instead, you or your doctor should determine if you have any of the common risk factors, get your blood sugar levels checked to determine if you have prediabetes, and then make the necessary lifestyle changes you need to stop type 2 diabetes from occurring."