Dear Doctor: I wonder if you could help me with a problem that robs me of sleep, and which lately even persists during the day. I’m referring to restless leg syndrome. What causes it? Are there any new findings about getting relief?

Dear Reader: Restless leg syndrome, which is also known as Willis-Ekbom disease, is a condition in which someone has an uncontrollable need to continually move or flex the muscles in their legs. This is due to unusual and unpleasant sensations such as throbbing, crawling, pulling, tingling or itching, which only subside during movement.

Restless leg syndrome, or RLS, can happen to anyone and at any stage of life. Up to one-third of pregnant women report that they experience RLS symptoms, and the condition occurs in children as well. It’s seen more often in women than in men, and it is most common among older adults. Although it can affect any part of the body, most people experience symptoms in the muscles of their calves or thighs.

RLS symptoms, which become more frequent in the late afternoon and evening, typically begin when someone is at rest. The sensations are so persistent they can’t be ignored. Although flexing the muscles, standing or walking can bring relief, as soon as someone is at rest again, the symptoms return. Like you, the majority of people living with RLS also experience twitching and jerking movements that interfere with sleep. These can occur two or three times per minute throughout the night and often lead not only to sleep deprivation, but also to anxiety and depression.

Although the exact cause of RLS remains unknown at this time, research links it to a disruption in a region of the brain known as the basal ganglia, which is associated with movement. This part of the brain uses dopamine, a brain chemical crucial to smooth and sustained motion. There is also evidence that low levels of iron in the brain may play a role. Drug treatment focuses on opioids, medications to amplify dopamine, antiseizure drugs and certain sleep medications. Each of these comes with potential side effects, so it’s important to discuss the pros and cons with your doctor.

Lifestyle changes such as a moderate exercise program, stretching, massage, warm baths, cutting back on alcohol and tobacco use, and the use of heat or ice packs can ease symptoms. Some people with RSL find relief with a foot wrap, approved by the FDA, which applies pressure to two muscles in the foot. Another device provides pressure and vibration along the backs of the legs. Both of these have been found to help ease RLS symptoms.

A small study by researchers at the Stanford Center for Sleep Sciences and Medicine recently found that people with RLS may have an imbalance in certain kinds of bacteria in their gut. This echoes the gut-brain connection currently being explored in Parkinson’s disease, which also involves a loss of dopamine that affects movement. More research is needed, but this line of inquiry holds promise for new and more effective directions in 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: Our son will be 3 years old when his baby sister arrives this fall. What can my husband and I do to help him understand the changes that are on the way?

Dear Reader: Congratulations on your growing family, and also on planning ahead for a major change in your son’s life.

At this point, you’ve mastered the baby basics that were probably daunting when your son first came home, such as, well, just about everything. Now you and your husband, along with your toddler, face a new learning curve. You’ll be juggling the care of two young humans at different stages of development, and your son will be coming to terms with his new role as the older -- and no longer only -- child. The steps you take as your pregnancy progresses, as well as how you integrate your new daughter into family life, will go a long way to smoothing the transition.

Start by talking to your son about the coming baby. As a toddler, his ability to grasp either the scope or the details is limited, so use visual examples to help bridge the gap. If someone in your circle of friends and family has a baby, see if you can arrange for your son to meet and spend time with them. (You may have to do this virtually for the time being.) If possible, repeat these visits throughout your pregnancy.

Make a game out of spotting infants when you’re out and about in the world. Get one or two of the many excellent picture books available about the birth of a new sibling and read (and reread) them together. When your pregnancy has progressed enough, let your son feel the baby’s movements. Explain that his new sister can hear him, and encourage him to talk and sing to her. If you’ve decided on a name for your new arrival, use it when talking about her.

This is a great time to break out the family photo album and show your son pictures of you while you were pregnant with him, as well as of his first few months of life. Telling a simple but specific story about each photo will not only help the images become real, it will let your son know he has a solid place in your family’s history.

Pediatricians often recommend buying a life-sized baby doll and using it to practice contact, as well as caregiving activities. Include your son in the preparations for the baby. Toddlers love color and shape and texture, and letting him in on decisions for decor and toys for the new baby’s room will give him a sense of ownership and control. And -- very important -- your husband should be actively involved in each of these steps as well.

Don’t be surprised if your son becomes anxious and clingy as your due date approaches and once the new baby is home. It’s common for young siblings to regress a bit at this point. Just continue to give him love, reassurance and one-on-one private time, and be patient as everyone adjusts to their new roles.

(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: I just read that a coronavirus vaccine won’t be ready until at least next year. How do vaccines work? And why do they take so long to make?

Dear Reader: When measured against the catastrophe of the current pandemic, the estimate of 12 to 18 months to develop and launch a coronavirus vaccine seems like an eternity. But, believe it or not, the proposed timetable is actually extremely fast.

A vaccine is basically a lesson plan that teaches the body how to recognize and eliminate a specific pathogen. It works by introducing the immune system to molecules known as antigens, which are the distinctive sugars and proteins that dot the outer surface of a bacterium or virus. The immune system reacts by sending antibodies to disable or destroy the pathogen. But matching the correct antibody to a brand-new pathogen takes time. So does producing enough antibodies to deal with all of the invaders.

A vaccine gives the body a head start. It presents the immune system with either a harmless form of a virus or bacterium, or with bits of antigens. Each will prompt the immune system to produce the antibodies it needs to attack that particular pathogen. The next time that unique antigen signature is detected, the immune system is ready and able to attack before the pathogen has time to make you sick.

Vaccines can take up to 10 years to develop. That’s due to the multiple phases of rigorous testing it takes to make sure a vaccine is not only effective, but also safe. It begins with work in animal models to understand how both the virus and the vaccine behave in the body. The next step is a Phase I trial, in which the vaccine’s efficacy is tested in a small group of healthy volunteers. This typically takes a year or two, but that may be scaled back to three months for a COVID-19 vaccine.

A larger Phase II trial, which further evaluates the vaccine and involves the use of placebos, usually takes two to three years. For the current vaccine, this may be shortened to eight months.

In Phase III, which also includes placebos, the vaccine is tested on thousands, or tens of thousands, of volunteers. Again, the typical timeline of two to four years is expected to be significantly shortened.

The next step is regulatory review of the clinical process, followed by production and distribution, each of which also take time. Post-approval studies are used to monitor how effective the vaccine is in real-world conditions.

Thanks to previous research into other types of coronaviruses, including those that caused the SARS and MERS outbreaks, scientists have a bit of a head start. They also are using a new and faster technique to develop the vaccine, based on genetic information known as messenger RNA. This has all led to the mid-March launch of a Phase I trial with 45 volunteers at the Kaiser Permanente Washington Health Research Institute in Seattle. It’s a significant first step in what will be a challenging and closely watched process.

(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.)