Diseases & Conditions Archive

Recent findings raise concerns about lowering diastolic blood pressure — the second number in your blood pressure reading — too far.

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More of us than ever before are taking medications to lower our blood pressure. Longstanding guidelines suggest that most people should aim for a systolic blood pressure (the first number in a reading) no higher than 140 millimeters of mercury (mm Hg). But in 2015, the results of the Systolic Blood Pressure Intervention Trial (SPRINT) suggested that reaching a target of 120 mm Hg could further reduce the risks associated with high blood pressure, including heart attack, stroke, heart failure, and death.

Yet reaching that lower target often requires three blood pressure medications, which can increase the likelihood of side effects. Two observational studies and one clinical trial have raised concerns about lowering blood pressure — particularly diastolic pressure — too far. Diastolic blood pressure (the second number in a reading) represents the pressure between beats when the heart relaxes. "When your systolic blood pressure gets too low, it can manifest as lightheadedness, fainting, and weakness. But low diastolic pressure by itself doesn't have any symptoms," says Dr. Paul Conlin, professor of medicine at Harvard Medical School and chief of medicine at the VA Boston Healthcare System.

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.

Three telltale symptoms occur in 75% of all strokes, often in combination. Don't ignore them — even if they're short-lived.

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Every 40 seconds, someone in the United States has a stroke. Also known as "brain attacks," strokes result from an injury to a blood vessel that limits blood flow to part of the brain. Rapid diagnosis and treatment can prevent potentially devastating disability or death — which is why everyone should know the common warning signs of a stroke.

In 2013, the American Stroke Association unveiled a stroke awareness campaign based on the mnemonic FAST. Around that the time, a national survey suggested that 28% of Americans didn't know any stroke symptoms, and nearly half weren't sure what to do if they experienced or witnessed the symptoms of a stroke. But four years later, things seem to be improving.

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?").

Most people who are suffer from fecal incontinence do so in silence. As a result, the number of people with the condition — which results in the involuntary release of gas or stool — isn't known. But the scant evidence at hand indicates that it usually begins during one's 40s or 50s.

You don't have to live with incontinence — there are treatment options, which include dietary changes and bowel training regimens, and surgery for some people.

Those extra inches around the middle may signal increased fat around abdominal organs and rising health risks.

It's a rare woman over age 50 who has the same waist measurement she had as a teenager. But in the past decade or so, women's waistlines have been expanding regardless of age. A 2014 report from the National Health and Nutrition Examination Survey found that from 1999 to 2012, the average body mass index (BMI) for women age 20 or older held steady. But during the same period, the average female waistline grew slowly and steadily, from 36.2 inches to 37.8 inches. Researchers are still searching for an explanation for this phenomenon, but they do know one thing: increasing waistlines are linked to greater risks for heart disease, diabetes, and osteoporosis.

What's in a waistline?

Regardless of whether your weight has changed over the years, your height is likely to have decreased, the result of declining volume in the intervertebral discs of the spine. As your torso shortens, your abdominal organs have less vertical space to inhabit, so they move horizontally. If you haven't gained weight, an increase of an inch or two around the waist may simply reflect lost height.

This common type of arthritis can show up suddenly and cause debilitating pain.

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The great artists Ludwig van Beethoven, Luciano Pavarotti, and Leonardo da Vinci had more than extraordinary talent in common; they were also sufferers of a type of inflammatory arthritis called gout. You may be at risk of joining their ranks if you have any potential triggers for the condition. "Most people are surprised by their initial gout diagnosis, unless they have a strong family history," says Dr. Mark Fisher, a rheumatologist at Harvard-affiliated Massachusetts General Hospital.

About gout

Gout is mostly a man's condition, although women can experience it, too. It's caused by a buildup of uric acid — a waste product from the breakdown of natural chemicals called purines (an essential part of DNA).

Because medications cannot effectively treat aortic stenosis, a stiff, narrowed aortic valve needs to be replaced.

Your aortic valve is the gateway between your heart and body. With every heartbeat, it opens to allow blood to flow to your body, then snaps shut to keep blood from moving back into the heart.

As people age, calcium deposits may collect on the hard-working aortic valve, causing it to stiffen and narrow. Known as aortic stenosis, this condition also can result from a genetic abnormality (see "What is a bicuspid aortic valve?"). But most cases are in older people, often — but not always — those with high blood pressure, high cholesterol, and other risk factors linked to heart disease. In the United States, about three to four of every 100 people ages 75 and older have severe aortic stenosis.