Dear Doctor: My wife just had her yearly checkup, and when her blood test results came back, she was told that she had recently suffered a heart attack. How can that be, since she never had any symptoms?

Dear Reader: Your wife had what is known as a “silent” heart attack. Just as the name suggests, it’s a heart attack that occurs without the person realizing it happened. In many cases, though, it turns out the episode wasn’t all that silent after all. It’s true that the person didn’t experience the numb left arm or sudden chest pain that we all recognize from movies and television, often referred to as the “Hollywood” heart attack. However, upon review, many people will realize they were aware of different, subtler symptoms that signaled a heart attack was taking place.

A heart attack occurs when something causes the flow of blood to the heart to become blocked. Without the oxygen and nutrients supplied by a network of blood vessels known as the coronary arteries, the heart muscle begins to die. This causes an array of symptoms. The most commonly known symptoms of heart attack include pain and pressure in the chest, and pain or discomfort in one or both arms. Additional symptoms include pain or discomfort in the neck, jaw, back or stomach; nausea; light-headedness; dizziness; shortness of breath; sudden sweating; and fatigue. These can be so mild, brief or even innocuous that the person never connects them to a heart attack.

Studies suggest that silent heart attacks are more common in women than in men. Women are also more likely to experience symptoms that are unrelated to chest pain. People who have had a silent heart attack may later recall feeling dizzy or short of breath, having a bout of stomach pain or nausea, or experiencing a neck ache or unusual fatigue. These symptoms are easy to attribute to other causes, such as a case of the flu, stress, indigestion or a strained muscle. However, as in your wife’s case, blood tests will reveal elevated levels of a protein known as troponin T or troponin I. These are released into the blood when the heart muscle is damaged.

The risk factors for any type of heart attack are the same. These include a prior heart attack, a family history of heart disease, using tobacco products, high blood pressure, high blood cholesterol, being overweight, poor diet and lack of exercise. Age and race also play a role.

After someone has had a heart attack, they can make lifestyle changes to lower risk. These include quitting smoking; reaching and maintaining a healthy weight; adopting a healthful diet; managing chronic health conditions, such as diabetes; and becoming physically active. If appropriate, medications to control high blood pressure and high blood cholesterol will be prescribed.

If anyone has the symptoms of a silent heart attack, it’s important not to ignore them. Early treatment will not only lessen the amount of damage that is done to the heart, it may well save your life.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Would you please consider doing a recap about the coronavirus -- especially about how it spreads? There’s a lot of information floating around, and it’s getting hard to sort through the noise.

Dear Reader: It’s true that we’ve been deluged in recent months with coronavirus coverage. Whether in print, on TV, on the radio or online, the information ranges from accurate to speculative to deliberately false. All of this adds up not only to potential confusion, but also to mental fatigue. You’re not alone in feeling overwhelmed by the topic. And to be honest, just running through the facts as we know them thus far will be helpful to us, as well.

Let’s start at the beginning. The novel coronavirus goes by the name SARS-CoV-2, which stands for severe acute respiratory syndrome coronavirus 2. It’s referred to as “novel” because it has never been seen in humans before. This means we have no acquired resistance or immunity to this particular virus. The disease that SARS-CoV-2 causes is known as COVID-19. COVID stands for “coronavirus disease,” and the number 19 refers to the year that it first appeared, which is 2019. In fact, the first public information about the disease was released on Dec. 31, 2019, the last day of that year.

A growing body of evidence suggests the virus most commonly spreads via the tiny respiratory droplets we emit whenever we speak, cough, sneeze and breathe. These droplets can be inhaled, or may be transferred to the mucous membranes of the nose, mouth and eyes via touch. That’s why washing your hands and not touching your face are both so important. This is also why the Centers for Disease Control and Prevention now recommends that people in public places wear facial coverings, which constrain the movement of the respiratory droplets we all release. Since not everyone infected with SARS-CoV-2 develops physical symptoms, it is possible for these individuals to unknowingly transmit the virus. Again, that’s why facial coverings for everyone are so important -- you’re protecting the people around you. The typical range of expelled respiratory droplets is less than 6 feet, which has led to the buffer zone we are now all asked to observe.

Symptoms of COVID-19 appear about two weeks after infection. They include fever, dry cough, tiredness and shortness of breath. Also common is a sudden loss of the sense of taste and smell. Patients also report headache, muscle aches, chills and chest pain. Although older adults and anyone with a serious underlying medical condition appear to be at higher risk of serious COVID-19 complications, it’s possible for anyone of any age to become ill. And the disease appears to have a broader scope than the pneumonia it’s best known to cause. A rare inflammatory condition is now being seen children. And in a number of adults, a range of adverse reactions brought on by sudden and unexpected blood clot formation have been reported. Unfortunately, there is no cure for COVID-19 at this time. Anyone with symptoms should seek immediate medical care.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: Our daughter is only 4 years old, and she has had her first cavity already. What can we do to make sure that things go better at her next visit to the dentist, and for her new baby brother?

Dear Reader: Tooth decay is common in young children. Their small mouths can make thorough brushing a challenge, and a wriggling and impatient child only adds to the level of difficulty. In fact, studies show that one-fourth of all children have had at least one cavity by the time they turn 4. Fortunately, with consistent dental hygiene, good diet and regular visits to the dentist, you can prevent tooth decay.

Our mouths can play host to hundreds of different types of bacteria, many of them benign, and some even useful. But among their number is a bacterium known as streptococcus mutans, a sugar-loving organism that is responsible for the formation of cavities. Every time we eat, this bacterium gets a meal as well. And as it devours the sugars that linger in our mouths, it produces an acidic byproduct that gradually erodes the tooth’s enamel coating. That’s why brushing and flossing, as well as a diet that limits sugar, are crucial to good dental health. Fortunately, with a few simple steps that you follow every day, you can significantly reduce your child’s risk of developing more cavities.

Even before an infant’s first tooth emerges, you should gently wipe their gums and mouth with a clean, damp cloth after feedings. Their first tooth should be greeted with a soft infant toothbrush that you use for a gentle cleansing after each meal. Brushing with plain water is fine. If you do decide to use toothpaste at this point, make sure it’s a tiny amount, about the size of a grain of rice. As soon as your child has two teeth that touch each other, it’s time to begin flossing. Again, it’s important for you to be very gentle so as not to cause discomfort, pain or bleeding.

Children 3 and older should brush twice a day and continue flossing once a day. Young children are often not coordinated enough, or they lack the attention span, to do a thorough job. If that’s the case with your daughter, continue to brush her teeth for her until you’re sure she’s up to the task. Most kids need help brushing, or at least close supervision, until they’re 7 or 8.

Sugar increases the risk of developing cavities, so diet is also important. Limit sweets, sugary drinks and snacks between meals. And when kids do indulge, get them into the habit of brushing their teeth immediately afterward. All of this will be easier if you set a good example yourself. Be sure your kids see you brushing your teeth after meals, just as you’re asking them to. Ditto for daily flossing.

And don’t forget about the dentist, who will be an important lifelong ally in maintaining good oral health. The American Academy of Pediatrics recommends that kids see a pediatric dentist within six months after their first tooth appears, or by 12 months of age.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)