Dear Doctors: I had this scary episode happen where all of a sudden, it felt like the world wasn’t real. My heart was racing and I thought I was going to pass out. The friend I was with said it was probably a panic attack. Is there any kind of treatment? I really don’t want that to happen again.

Dear Reader: Not a day goes by in our practices without there being a discussion about anxiety or panic with at least one of our patients. In fact, the data collected by internet search engines shows that searches for the keywords “anxiety” and “panic,” which began to rise in March, have surged in recent weeks. Considering the length of time we have all been dealing with the many uncertainties of life during the pandemic, as well as the social isolation that it has caused, it’s not surprising that the rigors of this strange new normal are taking a psychological toll.

From what you described, it does sound like you had a panic attack. These often occur as an acute manifestation of anxiety. In addition to major life stresses such as a grave illness, job loss or the death of a loved one, people with a family history of anxiety disorders may be at increased risk of experiencing a panic attack.

The symptoms, which appear suddenly, include the rapid heartbeat and shortness of breath that you described. Additional symptoms include sweating, heart palpitations, chest pain, weakness, chills, nausea, stomach pain, numbness in the fingers or hands and trembling. For many people, a panic attack is accompanied by an extreme emotional or psychological response, which can include the feelings of unreality and disconnection that you experienced. People also report feelings of looming peril and of hopelessness. Most share your distress at the thought of having to navigate another panic attack in the future.

The first thing to know is that no matter how intense the experience, it’s temporary. If you should find yourself having another episode, try closing your eyes, bring your awareness inward and focus on taking deep, steady breaths. Breathe in deeply through your nose, to the bottom of your lungs, hold your breath for a beat or two, and then breathe out just as slowly. Some people find it helpful to count from one to five on each inhale and exhale. Be careful not to hyperventilate, which can make you feel worse.

Although a panic attack is frightening, it’s not dangerous. However, due to an overlap in symptoms with other health problems, such as a heart attack, getting a professional opinion is important. In addition to breathing techniques, many people find cognitive behavioral therapy, yoga and mindfulness to be helpful. Lifestyle changes, such as getting regular aerobic exercise, spending time in nature and steering clear of caffeine, nicotine, alcohol and recreational drugs, can make a difference.

If you continue to struggle with panic attacks, your doctor may prescribe anti-anxiety medications. Some of these can be addictive, though, and some have potential for abuse, so we discourage taking that path unless all other approaches have failed to bring relief.

(Send your questions to askthedoctors@mednet.ucla.edu. Owing to the volume of mail, personal replies cannot be provided.)

Hello again, dear readers, and welcome back to our monthly letters column. Once again, a column about the challenges of dealing with toenail fungus has brought a bumper crop of mail, with many of you sharing home remedies. Although the evidence for these types of natural agents remains limited, some people do find them helpful, and the approaches readers have shared here are not harmful.

-- A reader from Napa, California, had success with a friend’s approach. “I was plagued with this on both large toes, and several remedies, including Vicks VapoRub, didn’t help,” she wrote. “A friend recommended powdered Ajax cleanser, and that did the trick. A small amount on a nail brush used to scrub the affected nail every day was effective.”

-- A reader from Newport News, Virginia, also followed a friend’s advice. “I did everything I could to rid myself of the dreaded toenail fungus, and nothing helped. Then a friend suggested rubbing a capsule of vitamin E oil on my affected nails daily, and it worked!” she wrote. “Of course, it has taken awhile for the nails to grow out, but soon they looked normal again.”

-- Several readers shared that, although various home remedies for toenail fungus yielded temporary improvement, it was only when they used a systemic antifungal medication prescribed by their doctors that they saw long-lasting results.

-- In a column about gut health, we mentioned the benefits of fermented foods, including sauerkraut. We heard from a sauerkraut fan, who asked us to make clear the difference between the canned or bottled kind, which is pasteurized, and the fresh variety, which is not. “For years, I ate pasteurized sauerkraut, not realizing that all of the probiotics had been killed off through heating,” he wrote. That’s correct, and we thank him for the clarification. If you’re eating sauerkraut for the probiotics, be sure to shop the refrigerator case rather than the canned-goods shelf. If the label states the product has been pasteurized, it means the good bacteria have been killed during processing.

-- Regarding a column about motion sickness, we heard from several of you that, when you’re unable to be the one behind the wheel, keeping one eye closed can help keep nausea and dizziness at bay. We also heard positive feedback for the elastic wristbands we mentioned in the column, which keep a small plastic knob pressed into an acupressure point inside the wrist. “I use them in the car on windy roads, on ships and airplanes,” a reader wrote. “They are amazing, inexpensive and available at most pharmacies.”

-- Quite a few of you have asked us to clarify that both the mouth and the nose must be covered when wearing a face mask to slow the spread of COVID-19. This is important, because the newest research shows that the virus can spread not only through sneezing and coughing, but also through speaking and even breathing.

Finally, we’d like to close with a thank you to Mr. Carter. Your kind letter about these columns really made our day.

(Send your questions to askthedoctors@mednet.ucla.edu. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I’ve been diagnosed with breast cancer and really appreciate your recent columns on the subject. What can you tell me about Herceptin? My oncologist has suggested it for after chemotherapy is finished. What is it going to do?

Dear Readers: Herceptin is the brand name for a drug called trastuzumab. It’s a targeted therapy that’s often used in conjunction with chemotherapy to treat a certain type of breast cancer. Herceptin is one of a class of drugs known as monoclonal antibodies, which are lab-made proteins that play an important role in directing a patient’s immune response. It has also been approved for treating stomach cancers that have become metastatic, which means the cancer has spread beyond its original location and reached other parts of the body.

The fact that your doctor has recommended Herceptin suggests you have a type of cancer known as HER2-positive. That means the cancer cells have more than the normal amount of a certain type of protein on their surface. That protein is called human epidermal growth factor receptor 2, commonly shortened to HER2. Although the HER2 protein is present on the outside of all breast cells, some cancer cells have extra copies of the gene that makes the protein. When this is the case, it’s referred to as HER2-positive cancer, and it accounts for about one-fourth of all cases of breast cancer.

The presence of the HER2 protein makes these types of cancers more aggressive than those that are HER2-negative and plays a significant role in decisions as to the course of treatment. As a result, it’s recommended that all patients with invasive breast cancer be tested for their HER2 status. In addition to breast and stomach cancers, bladder, pancreatic and ovarian cancers can be HER2-positive. However, Herceptin has not been approved for use in all HER2-positive cancers.

Each cancer cell has an array of biologically active receptors on its surface. Herceptin works by preventing the HER2 receptors on a breast cancer cell from receiving chemical signals telling it to grow. The drug does this by physically binding to the receptors, which blocks and disables them.

The drug is most commonly delivered as an intravenous infusion. The first session takes about 90 minutes. Subsequent doses of the drug take about 30 minutes to deliver. A newer form of the drug is available as an injection.

As with most medications, Herceptin can cause a range of side effects. The most common include nausea, headache, fatigue, joint or back pain, diarrhea, weight loss and insomnia. The drug has been associated with heart problems, so your medical team will monitor your cardiac function during treatment. Because it can harm a developing fetus, it’s important to be vigilant about birth control during treatment with Herceptin, and for at least seven months after treatment has concluded.

The encouraging news is that treatment with Herceptin can be very effective, so much so that the advent of the drug has dramatically changed the prognoses for patients with this type of breast cancer.

(Send your questions to askthedoctors@mednet.ucla.edu. Owing to the volume of mail, personal replies cannot be provided.)