Dear Doctors: A co-worker is doing something called a parasite cleanse. She says if you have symptoms like gas, muscle aches, insomnia and feel hungry all the time, it means you have parasites. How would you get parasites, and how would you know? Does a cleanse really help?

Dear Reader: As with many odd and sometimes dubious health trends, you need look no further than social media for the popularity of the so-called “parasite cleanse” that your co-worker is following.

While the specifics of these cleanses can vary depending on the source, they typically focus on a cocktail of supplements that are supposed to clear the infection. To better understand the issue, we should begin by talking about parasites.

A parasite is an organism that lives on or within the blood, tissues or intestines of a host. It gets its food from the host, often at the expense of the host's health and well-being.

External parasites -- such as ticks, lice or mites -- are known as ectoparasites. In this case, though, we are talking about human intestinal parasites. These are divided into two categories: protozoa and helminths. Protozoa are one-celled organisms that are able to multiply within the host. Helminths are multi-celled organisms that fall into three main groups: tapeworms, roundworms and thorny-headed worms. While adult helminths do not proliferate in the intestines, they can produce eggs that are excreted in the host's feces.

The most common method of transmission of intestinal parasites is eating or drinking something that has been contaminated with feces from an infected individual. Helminth infections can also be acquired from soil in which infected feces is present. Helminth eggs can attach to produce and can be ingested in contaminated water. During a certain part of their life cycle, hookworms can actively penetrate skin. Contact with contaminated soil can result in infection. Living in a subtropical or tropical region, living with poor sanitation systems, having poor personal hygiene and lacking access to clean water increases the risk of acquiring a parasitic infection.

Symptoms of parasite infection can include abdominal pain, bloating, gas, diarrhea, anal itching, unexplained weight loss and exhaustion. However, these are common to a number of other conditions.

Just because someone experiences these symptoms does not automatically mean they have a parasitic infection. To determine that, and to learn the source of a potential infection, you need a medical diagnosis. This begins with a review of symptoms, information about recent travel and details about possible dietary exposure, such as eating uncooked meat or fish, or drinking so-called raw water, which has not been filtered or treated. If parasites are suspected, laboratory tests to analyze stool or blood will be used. When parasites are found, drug therapies specific to the infection are prescribed.

There is evidence that some of the ingredients commonly used in a parasite cleanse, such as wormwood, can be helpful. However, when symptoms and risk factors indicate a parasitic infection, a medical diagnosis, along with targeted treatment, are the best way forward. A parasitic infection can cause considerable harm and needs to receive proper treatment.

(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: I’m a 69-year-old African American male with high blood pressure. I get conflicting advice from my primary care doctors, and my BP readings are never taken under the same conditions. I'm confused and losing confidence in my medical network. Can I see a specialist for hypertension?

Dear Reader: As doctors, and also as patients, we feel your plight. Blood pressure, or BP, is an important metric in maintaining good health and well-being. Yet, accurate readings often pose a challenge. A primary reason for this is that blood pressure fluctuates, not only throughout the course of the day, but also from moment to moment.

The factors that can influence someone's blood pressure readings include general physical health, the medications or supplements they are taking, caffeine and alcohol usage, hydration, sleep, exercise, family history, their emotional state and even what they had for breakfast that morning. Check someone's blood pressure 10 times over the course of the day, and you will receive 10 surprisingly varied measurements.

Adding to the difficulty is that blood pressure readings performed in a medical office can run artificially high. It's common enough that there's even a name for it: “white coat hypertension.” For this reason, in our own practices, we worry less about the numbers arrived at in the office and focus more on readings taken when someone is at home. We advise patients to check BP in the morning, while they are feeling calm and rested. These readings are usually an accurate representation of resting BP.

In the trials used to arrive at blood pressure guidelines, participants are asked to sit quietly for a set period of time prior to BP readings being taken. The effects of blood pressure medications, which are typically dosed daily, last for 24 hours. The timing of these meds should not significantly affect BP readings. The goal, according to the current guidelines, is 130/80 for everyone.

Ambulatory blood pressure monitoring, which involves wearing a device that takes dozens of readings throughout a 24-hour period, is possible. However, we don't use this approach in our own practices. We find a week's worth of readings taken first thing in the morning will provide an accurate and instructive average.

When we see a significant difference between morning readings and those taken later in the day, when the stressors of daily life have kicked in, that introduces questions about the tone of the nervous system. With our patients, we will open a discussion about approaches to “training” the nervous system to become less volatile. This can include deep breathing, meditation or mindfulness exercises, or practices such as yoga and tai chi. Walking, weightlifting and simply being in nature have proven to be helpful in managing blood pressure.

As to your question about working with a specialist, it is certainly an option. When blood pressure is difficult to control, a cardiologist can be helpful. Kidney problems can also contribute to hypertension. For that reason, your primary care doctor may request certain tests to see if a kidney specialist, known as a nephrologist, would be a good choice.

(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, dear readers, and welcome to our monthly letters column. We'll begin with the news that lab-confirmed cases of influenza have been reported throughout the United States, which means our flu season is having another early start. Please make time to get your flu shot. This year, it's a quadrivalent vaccine that offers protection from two strains each of influenza A and influenza B.

Many of you have asked if the updated COVID-19 vaccine, which is tailored to the newest variants, can be administered at the same time as the flu shot. The answer is yes, you can get both shots at the same time. For those who do get sick with either the flu or COVID-19, being vaccinated decreases the severity of symptoms. And now, onward to your letters.

-- A reader who drinks bottled water asked about advice she recently received. "I have been drinking spring water from the store for many years because the water from my tap tastes bad," she wrote. "But someone told me spring water lacks minerals and I should stop. Is this true?" Both tap water and bottled water contain minerals. However, tests show that the mineral profiles of each vary, depending on the source. Unless you're drinking distilled water, from which all organic materials have been removed, you are getting minerals in your drinking water. But don't forget diet is also an important source of minerals. This includes foods like vegetables, leafy greens, fruit, seafood, shellfish, grains and dairy products. Eat a varied and balanced diet to be sure you get the minerals -- and vitamins -- your body needs.

-- A column about hyperhidrosis prompted a question from a reader. "I was diagnosed with hyperhidrosis and told to use a specific antiperspirant," they wrote. "It worked for a while, but then stopped. What else can I do?" With antiperspirants, it's important to apply them to completely dry skin. Existing moisture forms a barrier and limits the degree to which the ingredients can sink in. Try using a blow dryer prior to application to get the area as dry as possible. And, as we mentioned in the column, the FDA-approved use of Botox for hyperhidrosis has proven quite effective. Your doctor can prescribe this treatment.

-- We recently wrote about bats and rabies and are now hearing about a lot of close encounters. "Everything I read about bats says close contact should be considered possible exposure. Does this apply only if the bat physically touches you?" a reader asked. "I was down at the lake tonight in Montana and a bat flew by, maybe 5 feet away. Should I be concerned?" Just being near flying bats, while unsettling, does not put you at risk of rabies. That requires direct physical contact that results in a bite or a scratch. Rabies can spread from even minor scratches or bites, including those small enough to go unrecognized. But that requires direct physical contact. A bat that flies by can't give you rabies.

Thank you, as always, for writing. You've been generous with your correspondence, and we will be back soon with a bonus letters column.

(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.)