Dear Doctor: I read that a doctor knew that a woman had thyroid cancer just by seeing her neck on TV. Why was a visual diagnosis so easy? What happens next?

Dear Reader: The incident you're referring to took place in the spring of 2018, when a head and neck surgeon from New York was watching "Beachfront Bargain Hunt," a popular real estate show on HGTV. He noticed an area of swelling on the front of the home buyer's throat; when she turned her head or stretched her neck to look upward, the swelling became prominent enough that he believed it could be a thyroid mass.

Unsure of how to find the woman, he posted his concerns to his Facebook page. With the power of the internet, the surgeon and the home buyer were quickly put in touch with each other. He explained his suspicion and urged her to undergo diagnostic tests, specifically a sonogram and a fine needle biopsy. She followed his advice, learned that she did indeed have a malignant tumor, and immediately sought appropriate treatment.

Interestingly, this was not the first time that thyroid cancer has been diagnosed on HGTV. Several years prior, a nurse watching the popular home renovation show "Flip or Flop" discerned what she believed to be a tumor on the neck of one of the hosts. Her concerns proved to be correct. The tumor was malignant, and the host underwent successful treatment for his thyroid cancer.

The reason these tumors were visible is due to the location of the thyroid gland, which sits below the Adams apple and is just beneath the skin. The thyroid measures about 2 inches across and consists of two main lobes, which make it appear somewhat like a bow tie, or a butterfly. The gland produces the hormones used by the body to regulate metabolic rate. It also contains specialized cells that produce calcitonin, a hormone that plays a role in managing blood levels of calcium and phosphate. Diseases of the thyroid such as Graves' disease, hyper- or hypothyroidism, and thyroiditis often cause the entire thyroid to swell, which is referred to as a goiter. Thyroid cancers are more often asymmetrical swellings, and thus can be distinctive.

In addition to a visible tumor, symptoms of thyroid cancer can include trouble swallowing, difficulty in breathing, a persistent cough in absence of a cold and pain in the front of the neck that may radiate up to the ears. When thyroid cancer is suspected, diagnostic tests may include imaging of the gland, blood tests, a radioiodine scan to test thyroid function, and a biopsy to search for cancer cells. Depending on the type of cancer that is present, as well as the stage at which it is identified, treatment consists of surgery, radioiodine or hormone therapy, chemotherapy or radiation. Targeted therapies that enlist the aid of the immune system to fight the cancer are also now being used.

The good news is that the most common types of thyroid cancer are very treatable, with five-year survival rates of 98 percent. Both of the individuals in the HGTV diagnoses have reported successful treatment.

(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: My son and daughter are now 17 and 19, and my sister, who worries about everything, keeps telling me that STDs in teens are on the rise. Is this really true? If so, is there anything I can say to my kids? You know how teens are; will they even listen?

Dear Reader: Considering the context, we regret to inform you that your sister is correct. According to data collected by the Centers for Disease Control and Prevention, the rate of sexually transmitted diseases in the United States has hit a record high for the fourth year in a row, and a whopping 50 percent those new infections were acquired by young people aged 15 to 24 years old. It's estimated that one-quarter of all adolescent females who are sexually active currently have an STD, such as chlamydia or human papillomavirus, also known as HPV.

Despite an increase in the numbers of young people using condoms, which are an effective (but not foolproof) barrier against STDs, and the fact that teens and young adults are less sexually active and have fewer partners than did previous generations, the numbers continue to climb. Statistics show that adolescents between the ages of 15 and 19 and young adults between the ages of 20 and 24 have the highest risk of acquiring an STD.

This trend is believed to be the result of a complex combination of factors. A drop in federal funding for STD prevention education, as well as clinics for screening and outreach, has certainly played a role. So have cultural factors. The advent of effective antiviral drugs, which have turned once-deadly AIDS into a manageable chronic condition, may have also had the unintended effect of making other STDs seem less dangerous. Also at play may be the increasingly changing views of gender identity, with more young people having sexual partners of both sexes.

Whatever the cause, the spike in STDs in people of all ages is a serious concern. In their early stages, these diseases are asymptomatic, which makes it easy for an infected person to unknowingly transmit the disease. That's why baseline STD screening for young people who are sexually active is so important. In its later stages, each STD comes with its own serious health concerns. A number of viruses and bacteria have become antibiotic-resistant, which means problems continue even after seeking treatment.

The truth is the only foolproof way to avoid STDs is to not have sex. But whether or not your kids are sexually active, protection begins with education. That means teaching your kids about STDs and the grave health problems they cause. Stress using condoms as a barrier, even when other birth control methods are in use. As you point out, a single conversation probably won't be enough. Young people feel invincible, so this should be an ongoing dialogue. And don't forget about the HPV vaccine, which is recommended for preteens and young adults of both sexes. You'll find specifics at vaccines.gov/diseases/hpv.

Some parents fear the STD talk implies approval of sexual activity. In our opinion, it's an opportunity to state (or restate) your position on sex, and to offer up some stark reality.

(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: My family has a history of diabetes, and although I'm currently healthy (I exercise regularly and am careful about what I eat), I'm still curious about my blood sugar. Do you think it could be helpful to track it as a diabetic would, just so that I know how I'm doing?

Dear Reader: You've asked an interesting question about a growing practice among some non-diabetics. Diabetes is a group of diseases in which hyperglycemia -- that's elevated blood sugar -- results from disruptions to the body's insulin metabolism. Produced by the pancreas, insulin is the hormone that regulates blood glucose concentrations. People with diabetes either don't produce any or enough insulin, or can't properly use the insulin their bodies do produce. The cause of abnormal insulin metabolism determines which type of diabetes someone has.

This inability to manage blood glucose leads to levels that are abnormally high or low, each of which is dangerous. Low blood sugar can cause a rapid heartbeat, dizziness and heart palpitations. When severe, it can lead to seizures, unconsciousness and even death. When blood sugar levels are chronically high, there is risk of long-term damage to blood vessels, heart, kidneys, eyes and feet.

Managing blood sugar fluctuations is the goal of diabetes treatments. Depending on the type of diabetes that an individual has, this is achieved with diet alone, or through diet and insulin replacement. People are considered to have diabetes when a random blood sugar test measures above 200 mg/dL, or when they have a fasting blood sugar level of over 125 mg/dL. A fasting blood sugar level from 100 to 125 mg/dL is considered to be pre-diabetes.

All of which brings us back to your question. Regular blood sugar checks are crucial for people living with diabetes. Those with Type 1 diabetes use insulin and may need to test anywhere from four to 10 times daily. Type 2 diabetes can require two to three checks per day. And while we understand the impulse behind a non-diabetic wishing to track blood sugar, we don't see a clear benefit. The argument in favor is that, with routine monitoring, you'll learn how your body responds to specific foods, which may motivate you to make better dietary choices. Over time, however, the data will confirm what you already know. That is, complex carbs and foods high in protein don't cause the same spikes in blood sugar that you get from refined carbs.

The truth is that glucometers and testing supplies can be costly. A single test strip costs $1. Without a diabetes diagnosis, these are unlikely to be covered by insurance. The same goes for the new continuous glucose monitoring systems, which work via subcutaneous probes that test interstitial fluids. In our practices, diabetic patients already have a challenging time dealing with insurance coverage. We doubt whether insurance would cover the expense for a non-diabetic.

Instead, we think it would be wisest to continue on your current course, with exercise, good dietary habits and regular screenings with your family doctor. Be sure he or she knows about your family history of diabetes, as well as your concerns about developing the disease.

(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.)