Even children can be diagnosed with hypertension

Q: My nephew is 12 years old and was diagnosed with hypertension. I was surprised because I didn't realize this could be a problem for kids his age. I don't remember having my blood pressure checked as a kid. What information do you have about this?

A: No matter someone's age, blood pressure plays an important role in good health. Living with hypertension, which is chronic high blood pressure, puts you at increased risk of developing a wide range of diseases and conditions. These include heart disease, heart attack, heart failure, stroke, kidney disease, eye problems, vision loss and changes to cognition.

High blood pressure is known to increase the risk of microvascular disease. This is a type of heart disease that affects the smallest arteries that serve the heart. It can also lead to peripheral artery disease. This is a narrowing of the arteries that serve the legs, arms, stomach and head.

When someone develops hypertension as a child or teen, it greatly magnifies their risk of the condition following them into adulthood.

Tracking blood pressure in children can be a bit of a challenge. That's because the "normal" range depends on the child's age, height and sex. Accurate measurement also requires equipment that is sized and calibrated specifically for use in children. Once a child passes from adolescence and into early adulthood, another set of blood pressure metrics begin to apply.

As with adults, hypertension in children falls into two distinct categories. The most common is primary hypertension, also known as essential hypertension. This is high blood pressure that has no clear cause. The other category, known as secondary hypertension, arises due to an underlying disease or condition.

Health care providers use a person's medical history and family history to narrow down potential causes. Those findings can lead to additional blood and lab tests to help identify the cause.

At this time, the American Heart Association estimates that 2% to 5% of children in the U.S. are living with high blood pressure. That jumps to 25% among children who are overweight or obese. Research also shows that up to 75% of children living with hypertension go undiagnosed.

Because the condition is often asymptomatic, the AHA now recommends that blood pressure readings be included in a child's regular physical exams. Also, it takes more than a single elevated reading to establish a hypertension diagnosis. The AHA recommends using data from multiple readings, sometimes taken over the course of several months, for an accurate diagnosis.

Treatment typically begins with lifestyle changes. This includes reaching a healthy weight, adding exercise to daily life and sticking to a healthy diet. Unfortunately, vaping is now an issue, even among younger children, and must also be addressed. In some cases, it is possible that medications may be recommended.

If your child's health care provider isn't checking their blood pressure, don't be afraid to ask. Half of adults in the U.S. are living with hypertension. It's never too soon to start managing the problem.

Q: Our 9-year-old daughter fell off her skateboard and hurt her arm. It seemed like just a bad sprain, but after getting an X-ray, she was diagnosed with a greenstick fracture. What is that? Will it affect her in the future? She's in a cast for at least a month.

A: The term "greenstick fracture" refers to an incomplete break in a bone. It is different from other types of fractures, which leave the bone in two or even more distinct pieces. In a greenstick fracture, damage to the structure of the bone occurs only on one side.

These types of breaks are commonly seen in younger children who are still in the process of growing. Their bones are softer and more elastic than adult bones. This is due, in part, to microscopic structures known as Haversian canals. These are networks of tubules that bring blood and oxygen to the living tissues of the bone.

Haversian canals are lined with bundles of collagen, which is pliable. Juvenile bones contain higher numbers of Haversian canals than adult bones. They are more porous, and thanks to the additional collagen, more flexible.

Greenstick fractures typically occur in children under age 10, and they are sometimes seen in older children and even in teens. By young adulthood, however, bone structure has ossified. At that point, these types of incomplete fractures, while still possible, are rare.

Greenstick fractures of the arm are a common injury when a child tries to break a fall with an outstretched arm. They can also occur as the result of collisions while playing sports, car accidents and nonaccidental trauma, such as when a child is struck with an object. Vitamin D deficiency and other types of malnutrition can play a role in a child's susceptibility to a greenstick fracture.

As happened with your daughter, a greenstick fracture can cause minimal pain and may appear to be a sprain. In addition to pain and discomfort, symptoms can include stiffness, swelling, tenderness, bruising, warmth and weakness in the limb. In more severe breaks, a bend to the affected bone may be visible. Diagnosis is via imaging, whether an X-ray, MRI or CT scan.

With a simple fracture, treatment consists of immobilizing the bone with a cast. If a bone is visibly out of alignment, it will be necessary to manually straighten it prior to putting the limb into a cast.

If a break is severe, or when it involves nerve or tissue damage, surgery may be needed. Healing involves specialized cells, known as osteoblasts and osteoclasts, that gradually rebuild and fine-tune the new bone. Additional blood vessels, which support the rebuilding process, also form in the area.

The length of time a child spends in a cast can vary depending on the specific injury. Typically, that is four to six weeks. The good news is that our bones usually heal quickly and completely. And once the process is complete, the broken bone should be just as strong as it was before.

Q: After my best friend was diagnosed with breast cancer, she learned that she has a BRCA gene, and that it put her at risk of getting it. Now she's urging all of her girlfriends to get genetic testing. What is that, and how does it work? I'm actually afraid of learning something bad.

A: Genetic testing is a powerful tool that is used to reveal information about a person's body at a molecular level. It looks for changes or anomalies that may be present in someone's chromosomes or genes. It is also used to flag changes to specific proteins, which can affect the way they behave or function in the body.

These changes, which are known as mutations or variants, are often inherited. They also can be acquired during someone's lifetime. Acquired mutations can occur due to errors in replication as cells divide, or because something in the person's environment has damaged their DNA. Unlike genetic mutations, those that are acquired do not pass on to one's children.

The result of a genetic test can identify the existence of an inherited condition - such as cystic fibrosis, Huntington's chorea or sickle cell anemia - or it can help assess the chances that someone may someday develop a specific disease or condition, such as certain types of breast or colon cancer.

It can also determine the risk of a genetic disorder being passed on to future children, by identifying if either parent is a carrier of the associated chromosome mutation.

The results of a genetic test can help to diagnose a disease, guide subsequent treatment decisions, highlight the need for prevention strategies and help with family planning. When someone decides to move forward with this kind of testing, they often work with a genetic counselor. This is someone trained to offer guidance and support before, during and after the test.

The process itself involves gathering a sample of blood, saliva or tissue, depending on the test being performed.

Detailed information about personal and family health history is also reviewed. In our own practices, we refer a patient to a genetic counselor if there is a strong family history of cancer. The most common referral is for BRCA1 or BRCA2, which are gene variants linked to an increased risk of breast or ovarian cancer.

In addition to being positive or negative, results of a BRCA test can be inconclusive. This occurs when a gene variant is identified but has not previously been associated with elevated cancer risk. All of this makes genetic counseling a crucial part of genetic testing.

The world of genetics is evolving rapidly. We are now seeing companies that offer whole-blood DNA testing to the general public, including with information related to early detection of cancers. At this time, this sort of direct-to-consumer testing in the health arena is experimental. It is not part of mainstream care.

In the near future, however, we believe the rapid advances being made today will bring genetic testing into the realm of primary health care. If you believe that genetic testing may benefit you, your health care provider can help guide your decision.

• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.