Dear Doctor: My 58-year-old daughter has been diagnosed with postural orthopedic tachycardia syndrome. She's changed from a healthy active woman into someone who has spent most of the past two years in bed. A gamut of tests and medicines have failed to provide relief. What is this condition and what can be done about it?

Dear Reader: One reason we can move freely and make continuous changes to our elevation, including sitting up, standing up and rising from a prone position, is the series of complex adjustments performed by the nervous system, and by skeletal and respiratory muscle pumps. This fine-tuning lets the heart and blood vessels make the corrections needed to maintain steady blood pressure when we stand upright, and thus keep an even flow of oxygenated blood throughout the body and, most important, to the brain. When these adjustments are either inadequate or fail to take place, it's known as orthostatic insufficiency, or OI. And among the group of conditions that arise as a result of OI is postural orthostatic tachycardia syndrome, also referred to as POTS, which is the diagnosis your daughter has received.

When someone with POTS stands up (that's the "postural" part of the name), their blood immediately begins to pool in the lower portion of the body. With too little of the blood that it has pumped out now returning, the heart responds by suddenly beating quite rapidly, which is known as tachycardia. The immediate spike in heart rate -- at least 30 beats per minute, and often much higher the longer one stands -- is often accompanied by a drop in blood pressure. The resulting symptoms include dizziness, lightheadedness and fainting. Nausea, brain fog, shortness of breath, exhaustion, heart palpitations, shaking and chest pain may also occur. In some patients, a faint purple tinge can be discerned in the legs and feet, which is suspected to be the result of pooling blood. It's only when someone with POTS lies down again that an even blood flow is restored and the symptoms recede.

In the past, POTS was associated with anxiety, but researchers now understand it as a dysfunction of the autonomic nervous system. The syndrome can have a range of causes and at this time is not fully understood. As you have found, that makes finding an effective treatment quite difficult. Most treatments focus on addressing low blood volume and potential circulatory problems. Interventions range from simple things like adding salt to the diet and maintaining adequate hydration to medications such as beta receptor blocking agents.

Research into POTS is ongoing. A study published recently in the journal Neurology Today found POTS patients had high numbers of certain antibodies, pointing to a possible autoimmune connection. The website clinicaltrials.gov currently lists 64 studies into POTS, 12 of which are either actively or soon to be recruiting participants. POTS support groups, which connect patients and caregivers with others in their own area who are dealing with similar challenges, are listed at dysautonomiainternational.org. There's also an active POTS Facebook group with more than 6,000 members from throughout the world.

We wish we had more definitive answers for you and your daughter and hope that these resources will be of use.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My husband's mother had breast cancer, and so did both of his aunts. He's really worried about our two daughters' risk, but I've read that breast cancer can affect men as well. Shouldn't he also be worried about himself?

Dear Reader: Most breast cancer is diagnosed in women, but you're correct -- it occurs in men as well. One percent of all breast cancers are found in men. For men who inherited the BRCA1 or BRCA2 genes, the incidence of breast cancer rises to 6 percent. (The BR of BRCA comes from the word "breast," and the CA from the word "cancer.")

Both boys and girls have a small amount of breast tissue around and beneath the nipple. When girls reach puberty, their bodies make hormones that cause the growth and development of the glands and ducts that will make and carry milk, as well as the surrounding tissues to support those structures. Men have significantly lower levels of these so-called female hormones, so their breasts don't develop in the same way. However, men still have that slight amount of breast tissue. And though the small number of glands and ducts found in male breast tissue are not functional, they can still be the site of breast cancer.

Male breast cancer can occur at any age but is more commonly found in older men. In addition to age, risk factors for men include a family history of breast cancer and the inherited gene mutations discussed above. Other risk factors include exposure to whole-chest radiation, as in certain cancer treatments, and liver disease. That's because one of the liver's many roles is the balancing of our sex hormones. In severe liver disease, hormone levels can become skewed and lead to an abundance of estrogen, which raises breast cancer risk.

As with all cancers, early detection is important. Since men have less breast tissue, lumps or other abnormalities can be easier to find. However, that same lack of tissue means there's less distance for cancer to travel and spread to surrounding tissues. Another factor is the lack of awareness that male breast cancer exists, which makes it easy to ignore warning signs. For men with a history of breast cancer in their families, as with your husband's, performing regular breast exams is a good idea. In addition to lumps, keep an eye out for changes to the skin or nipple, including redness, scaliness, dimpling or puckering, discharge from the nipple, and breast or nipple pain.

If anyone in your or your husband's family has the BRCA mutation, then your husband may want to consider genetic testing. If he does decide to follow through, we strongly recommend enlisting the help of a genetic counselor. At the very least, this family history of breast cancer should be information that your husband shares with your family doctor. When caught in the earliest stages, which accounts for close to half of all diagnoses, the five-year survival rate for male breast cancer is 100 percent. We can't think of a better reason to become vigilant.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My wife and I worry about how social media rules the lives of all four of our teens, especially our two daughters. I get that there must be some upsides, but mostly we see it making the kids stressed and anxious. Are we overreacting? Should we take their phones away?

Dear Reader: When you consider that the era of social media is already 15 years old (remember Myspace, which launched in 2003?), it means that today's teens have never lived in a world without it. According to a recent survey from the Pew Research Center, 95 percent of teens either own a smartphone or have regular access to one. Ninety percent of teens say they go online multiple times per day, while almost half report being online "almost constantly."

While there can be real benefits to this kind of connectedness, it has become clear that the potential for negative behaviors and experiences is all too real. On the plus side, there is the chance to expand social circles and strengthen existing friendships.

But social media sites are also ripe for bullying, spreading rumors, ostracism and peer pressure. Another challenge is the stress associated with curating a social media presence, as well as the unrealistic expectations that get generated regarding physical appearance. And then there's the fact that this all takes place on public platforms and in real time, where the number of "likes" and the tenor of comments can wreak havoc on a teen's sense of self-worth. It's not surprising that you, like so many parents, are seeing your kids struggle.

When it comes to anxiety, no, you're not overreacting. Anxiety now tops depression as the main mental health issue among teens and young adults. That's not to say social media is the sole reason for this, but recent studies cite it as a contributing factor. Our teens grew up at the same time as the social media landscape. In a way, these kids have been the unofficial test subjects of this new means of social connection. And while it's tempting to ditch the smartphones and cancel the family's mobile plan, the truth is that social media is here to stay.

Instead, you're going to have to wade into the fray yourselves.

First, identify and learn the apps your kids are using. Snapchat and YouTube are the most popular at the moment. A year from now, it will likely be something different. The more you understand about the workings and nuances of your child's online platforms, the more likely she or he will be able to talk to you about them and to accept help if it's ever needed.

The goal here isn't to spy on or even "friend" your kids on social media, but to become fluent in the world that has so much of their attention. We also think it's a good idea to implement a family program -- that means kids AND adults -- of screen hygiene. Put devices away during homework, during meals and at bedtime. Yes, you're worried about the kids, but we know from experience that the grown-ups in the room can benefit from this kind of media fast as well.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)