Dear Doctor: My husband was in the hospital recently, and at night he would get quite agitated. He yelled, took off his clothes and tried to pull out his IV. He had to be secured to his bed to keep him from leaving. But in the morning, he'd be fine and couldn't remember anything from the night before. What's happening? How can I help?

Dear Reader: What you've described is a few of a group of behaviors commonly known as sundowning, or sundowner, syndrome. It's a descriptive term, not a psychiatric diagnosis. However, it's broadly recognized as anxiety, confusion or agitation that is triggered by the onset of waning daylight. Sundowning can begin anywhere from late afternoon to late evening, and usually resolves in the morning, with the return of daylight.

In addition to the symptoms that you mentioned, people may have mood swings, become demanding, suspicious or even paranoid, hallucinate, hear voices, pace or become unaware of time and place. While sundowning is most commonly observed in people with dementia, impaired cognition and Alzheimer's disease, it can also affect individuals who are institutionalized.

Exactly what causes these behaviors to develop isn't yet known. However, in addition to the low light and emerging shadows that give the syndrome its name, triggers can include fatigue, sleeplessness, lack of mental stimulation, disrupted circadian rhythms and the presence of an infection, such as a urinary tract infection.

To see your loved one vanish into the throes of sundowning is upsetting and painful. But once an episode has begun, neither logic nor coaxing can help. Don't try to talk or reason the person out of their fears. If they are hallucinating, don't try to bring them into the present. The best thing you can do is stay calm and be reassuring.

Over the long term, approaches to managing this behavior include:

-- Set up a daily routine with consistent waking and bed times, and regular mealtimes. This will form a predictable framework that can help the individual feel safe.

-- Schedule any taxing activities for early in the day, when the person is at their best. Try not to do more than one or two significant activities, like a doctor's appointment, a shopping trip, or visits from friends or relatives, per day.

-- Watch the diet for any possible triggers. If it turns out that caffeine and sugar cause problems, consider eliminating them, or limit them to earlier in the day.

-- As daylight fades, turn on lots of lights and close the curtains. Limiting noise can also be helpful.

-- Check with your family doctor to see whether a supplement like melatonin may help with sleep cycles.

We are keenly aware of the mental and emotional challenges of being the caregiver at a time like this. That's why we think it's so important that you take time -- make the time -- to care for yourself as well. Take regular breaks, enlist outside help and see a counselor to help process what you're going through. It will bolster your own health and will help you to be an even more effective caregiver.

And if any of you readers have successful strategies we haven't mentioned that you'd like to share, we'd love to hear from you.

(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: Could you explain panic attacks? I never knew what people were talking about until a few months ago, while sitting at the computer. I felt as if I had stopped breathing; I thought I was dying. I ended up in the ER, but no problems were found. This has happened several times since, and I want my life back.

Dear Reader: Panic attacks are truly a scary experience, especially if you've never had them before. Many of the symptoms are similar to those of a heart attack, causing people to seek immediate attention in an urgent care department or emergency room. The symptoms, which develop suddenly, can include chest pain, heart palpitations, sweating, nausea, shortness of breath, lightheadedness and, for many, the feeling that they're going to die.

Such attacks are surprisingly common. One-third of people have at least one panic attack during their lifetime. Those who experience recurrent panic attacks not related to generalized anxiety, depression, obsessive-compulsive disorder or post-traumatic stress disorder have what is termed panic disorder. People with panic disorder have a persistent worry about having another panic attack and the consequences of future attacks. That leads them to avoid situations that may induce panic attacks, which, in turn, leads to a profound alteration in quality of life. Panic disorder affects nearly 3 percent of the population, ages 15 to 54.

People with panic disorder often report an increase in stressful life events over the past year and, even more often, within the past month. Genetic factors also play a role. A person who has a first-degree family member with panic disorder is three times more likely to develop the disorder compared to people without such a tie. Further, an identical twin is five times more likely to have anxiety and panic if his or her twin has the disorder.

The symptoms of panic attacks are essentially a normal "fight or flight" response to a very stressful situation, such as an encounter with a lion, tiger or grizzly bear. However, panic attacks occur without the lion, tiger or bear. Some experts hypothesize that panic attacks are abnormal central nervous system responses to even the most mundane stimuli. Such responses arise in the brain's limbic system, which normally processes sensory information into emotional responses, behavior and memory. The hyperresponsiveness to sensory inputs -- and even the inputs from one's own thinking -- leads to a poor regulation of the autonomic nervous system, which controls heart rate, the contraction of the heart, blood pressure, the gastrointestinal system and sweating. MRI studies have confirmed alterations in the limbic system in people with panic disorder.

Panic attacks can also be precipitated by stimulants such as caffeine, cocaine and amphetamine as well as withdrawal from alcohol, opiates or benzodiazepines like Valium, Ativan and Xanax. Although patients sometimes use benzodiazepines to stop a panic attack, these medications can induce rebound panic when the drug is out of the system, making them a poor treatment option.

Cognitive behavioral therapy shows the greatest sustained benefit in stopping panic attacks, because it can alter the underlying brain responses. Selective serotonin reuptake inhibitor medications also can help.

In summary, starting therapy and possibly medication will be the first steps in getting your life back.

(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: A lot of my friends are talking about pickles these days because they're a way to get probiotics into your diet. But I read that pickled foods are associated with higher rates of cancer. Are pickles good or bad for you? I'm confused.

Dear Reader: While it's true that researchers have identified the consumption of pickled vegetables as a potential risk factor in certain gastric cancers, it doesn't necessarily mean you have to ditch those delicious dill spears that came with your sandwich. In the big picture, the data suggest a link between pickles and some cancers, but when you drill down into the details, it turns out that additional factors appear to be at play.

Let's start with pickles themselves. Virtually every culture in the world has a tradition of pickling. Methods vary, but most use some combination of salt, liquid and sometimes oil to induce and support fermentation, which preserves food for use beyond its growing season.

In the United States, cucumbers and cabbage account for the majority of pickled vegetables. At just 4 pounds per person per year, they're treated as a condiment. However, in many other parts of the world, including China, Japan, Korea and Turkey, a wide range of fermented vegetables (as well as fruit, soy products and sometimes meat) are a dietary mainstay, eaten daily for nine to 12 months of the year.

The idea of a pickle-cancer link arose when scientists began to look at cancer registries established in China in the 1960s. As researchers crunched the numbers, they found a high rate of gastric cancer in regions where pickled foods were eaten daily throughout the year. Since then, though, other groups of researchers have analyzed a wide range of these studies. They found that differing methodologies, as well additional lifestyle factors, made the direct link between pickles and cancer more tenuous.

In some cases, the populations being studied also ate high-fat diets and a lot of barbecued meat, both of which have a link to increased cancer risk. In other study groups, smoking was widespread and thus also implicated in potential disease. And, finally, there were the pickles themselves.

For example, a traditional way of pickling vegetables in parts of China involves packing them in salted water, sometimes seawater, for a period of weeks or months. During this time, fermentation occurs. However, the process also produces yeasts and fungi, some of which have the potential to produce compounds that are carcinogenic. A combination of the pickling method and the volume of vegetables consumed could be a factor in the higher gastric cancer rates.

In the U.S., by contrast, most commercially produced pickles are made without fermentation, in a process that uses vinegar and pasteurization. Although this eliminates the risk posed by those carcinogenic compounds, it also means these pickles won't be a source of probiotics. In addition, pickles are high in sodium, with a single dill pickle packing a hefty 50 percent of a day's supply of sodium.

Bottom line, with what we know now: Whether it's fermented or commercial pickles that you're eating, moderation is the key.

(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.)