Dear Doctors: Can you help with a debate my wife and I are having about good balance? I say it’s about staying strong and flexible. She thinks it has to do with your inner ear. We’re arguing about this because her dad, who is 75 and in good health, has started to worry about balance.

Dear Reader: For the sake of family harmony, we’re glad to be able to say that you are both correct. Your sense of balance is actually quite complex, and the inner ear, as well as strength and flexibility, each play an important role.

Balance begins with a nonstop stream of information gathered by several systems in the body. These include the eyes, which are part of the visual system, and which help you to orient yourself in space. The muscles, joints and tendons, which are part of the musculoskeletal system, contain special sensors that provide something known as proprioceptive input. Sometimes also referred to as kinesthesia, it’s the body's ability to sense its own movement, actions and location. The inner ear contains something known as the vestibular system. About the size of a quarter, it’s an intricate structure made up of fluid-filled canals, sacs and cavities that are lined with fine hairs and other specialized cells. It provides information about head position, spatial orientation and motion. All three of these systems are continually sending their findings to certain areas of the brain. This flood of data gets processed, and the result is the ability to stand, move and perform tasks and remain balanced.

The other important components of balance are, as you have pointed out, strength and flexibility. Both are required to keep the body upright and under control. Good balance relies on the muscles of the feet, legs, buttocks, abdominals and torso. And, yes, that’s basically the entire body.

Resistance training and weightlifting will build strength and stamina, while practices such as yoga, tai chi, Pilates or targeted stretching exercises will help with flexibility. Simple things, such as standing on one foot for a period of time while watching TV or waiting in a line, always rising from a chair without an assist from your arms, practicing walking backward or walking heel-to-toe in a straight line all directly target balance.

And while this may come as a surprise, it’s not just older adults, like your father-in-law, who need to think about stability. Researchers have found that balance begins to decline in midlife, starting at about age 50. In one recent study, adults in their 30s and 40s could stand on one foot for a minute or more. At age 50, the time decreased to 45 seconds. At 70, study participants managed 28 seconds. By age 80 and older, they lasted less than 12 seconds standing on one foot. Just as sobering is the fact that one-third of adults 65 and older suffer a fall each year, with outcomes ranging from a bruise or a sprain to broken bones and concussion -- or worse. A focus on balance is a great idea for your father-in-law, and for you and your wife, as well.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: My friend works for a pediatrician. He said the staff have been told to look out for a liver disease that’s getting kids sick. What are the symptoms? Is this related to COVID-19? Our kids are back in school, and, needless to say, after the last few years, we’re on edge about their health.

Dear Reader: Your friend is referring to a health advisory issued by the Centers for Disease Control and Prevention in April. The agency is asking physicians and other medical personnel to be aware of unusual cases of severe hepatitis in children.

The alert was issued after a large children’s hospital in Alabama notified the CDC of five cases of serious inflammatory liver disease, which occurred last November. All five children, who previously had been healthy and had no history of liver problems, suffered significant injury to their livers. Three of the five had acute liver failure.

While liver disease in children is not rare, a cluster of this type raises alarms. The hospital then examined patients’ medical records dating from October 2021 to February 2022. They identified a total of nine cases within that five-month period, two of which required a liver transplant. Although all nine children, who ranged in age from 1 to 6, became ill enough to need hospitalization, none have died. At least two additional cases have been reported in North Carolina.

Laboratory testing ruled out the viruses that cause type A, B, C and E hepatitis. None of the children had COVID-19, and none had received a COVID-19 vaccine. However, further testing showed that each child had been infected with a certain type of adenovirus. This is a group of more than 100 viruses, many of which cause coldlike symptoms, and several are known to trigger significant inflammation.

The circumstances here in the U.S. echo similar clusters of sudden and severe pediatric liver disease that occurred at the start of the year in the United Kingdom and were later identified in Europe. One child has died, and more than 179 cases are now being investigated. Although a cause has not been identified, health authorities are investigating the possibility of a connection between adenovirus infection and these cases of pediatric hepatitis.

The word “hepatitis” means inflammation of the liver. The cause is often infection by a virus. Because the liver is a vital organ and inflammation can adversely affect some or all liver functions, hepatitis is a potentially life-threatening condition. As well as filtering toxins, waste products and worn-out cells from the blood, the liver performs hundreds of additional functions. These include processing and storing nutrients, producing bile, making cholesterol and certain blood proteins, storing iron, regulating blood clotting and helping to fight off infection.

Symptoms of hepatitis include jaundice, which is yellowing of the whites of the eyes or the skin; abdominal tenderness or swelling; fever; urine that is dark in color; light-colored stools; unexplained fatigue; and nausea or vomiting. If your child has any of these symptoms, it’s important to seek medical care.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Hello again, dear readers, and welcome back to the monthly letters column. Virus-related mail, which once required a column of its own, has slowed down. That means we can once again fold those questions in with the general letters. Speaking of which ...

-- Recommendations regarding COVID-19 booster shots have caused some confusion, including for a reader from North Carolina. “Do you know if a second booster will be available soon for elderly persons with no severe autoimmune problems?” she asked. “I had the first booster more than five months ago.” You are indeed eligible for a second booster. As of March 29, the CDC recommends a second booster for adults over the age of 50 whose previous booster was four or more months ago.

In addition, all adults who had the Johnson & Johnson vaccine and first booster are eligible for a second booster using an mRNA COVID-19 vaccine. Again, the timing is four or more months after the most recent shot.

-- On the topic of supplements to deliver omega-3 fatty acids, a reader wondered about dosage. “I’ve been a vegetarian for 40 years and use flaxseed oil to supplement my intake of omega-3 fatty acids,” they wrote. “The FDA recommends a maximum of 3 grams per day, but my flaxseed oil has 8 grams per serving. Is that too much?”

For adults 51 and older, the recommended daily intake of omega-3 fatty acids is 1.1 grams for women and 1.6 grams for men. The reason for the cap of 3 grams per day is that when taken in high doses, omega-3 supplements can cause blood thinning, lead to excessive bleeding and interact with prescription drugs that affect blood clotting. Unless your doctor has recommended the dosage you are now taking, it’s a good idea to find a product that meets the recommended guidelines.

-- We heard from a reader whose prescription medications frequently change shape and color, which led to a dangerous mix-up. “I recently had a scary episode after mistakenly taking two doses of one blood pressure drug instead of one each of two different drugs, and it made me quite ill,” they wrote. “In the 15 years I have taken these drugs, they have come in five different colors and four different shapes. Does the FDA pay attention to the risks of color and shape changes?”

While the FDA oversees the contents of medications, the shapes and colors are chosen by each manufacturer. And due to patent laws, manufacturers of generic versions of brand-name drugs are not allowed to copy appearance of the originals. Because pharmacies sometimes change suppliers, the same generic medication from a new manufacturer can suddenly come in a different color or shape. This can be confusing and, as happened to you, even dangerous. While it’s not a perfect answer, some patients find using pill organizers can make things less complicated.

As always, thank you to everyone who took the time to write. Our mailboxes are overflowing, so we’ll be adding a bonus letters column in the next few weeks.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)