Some research suggests that infant swimming in chlorinated pools might increase the risk of airway inflammation, but there isn't enough information conclusively linking infant swimming and asthma to warrant keeping healthy babies out of indoor pools.

Researchers theorize that chlorine — a common disinfectant used to keep pools clean — binds with swimmers' sweat, dirt, skin cells and urine to create byproducts in the water and air that might harm an infant's lungs and put him or her at risk of developing asthma. Indoor pools have higher concentrations of these byproducts than do outdoor pools. Babies might be at particular risk because their lungs are still developing and they tend to swallow irritant-laden water while swimming.

Studies examining the relationship between infant swimming and asthma, however, have produced conflicting results and further research is needed.

If your baby participates in infant swimming in indoor pools and you're concerned about asthma, opt for a well-ventilated facility. Ideally, staff members will open doors and windows in the pool area and use fans to boost airflow over the surface of the pool when it's crowded. Also, rinse yourself and your baby in the shower before entering and after leaving the pool, wear a swim cap, and regularly check your baby's diaper. This can reduce the formation of irritants in the water and air.

Waking up in the middle of the night is called insomnia, and it's a common problem. Mid-sleep awakenings often occur during periods of stress. Over-the-counter sleep aids rarely offer significant or sustained help for this problem.

To help stay asleep through the night, try some of these strategies to relieve insomnia:

• Establish a quiet, relaxing bedtime routine. For example, drink a cup of caffeine-free tea, take a warm shower or listen to soft music. Avoid prolonged use of electronic devices with a screen, such as laptops, smartphones and ebooks before bed.
• Relax your body. Gentle yoga or progressive muscle relaxation can ease tension and help tight muscles to relax.
• Make your bedroom conducive to sleep. Keep light, noise and the temperature at levels that are comfortable and won't disturb your rest. Don't engage in activities other than sleeping or sex in your bedroom. This will help your body know this room is for sleeping.
• Put clocks in your bedroom out of sight. Clock-watching causes stress and makes it harder to go back to sleep if you wake up during the night.
• Avoid caffeine after noon, and limit alcohol to 1 drink several hours before bedtime. Both caffeine and alcohol can interfere with sleep.
• Avoid smoking. In addition to smoking being a major health risk, nicotine use can interfere with sleep.
• Get regular exercise. But keep in mind, exercising too close to bedtime may interfere with sleep.
• Go to bed only when you're sleepy. If you aren't sleepy at bedtime, do something relaxing that will help you wind down.
• Wake up at the same time every day. If you experience increased awake time during the night, resist the urge to sleep in.
• Avoid daytime napping. Napping can throw off your sleep cycle.
• If you wake up and can't fall back to sleep within 20 minutes or so, get out of bed. Go to another room and read or do other quiet activities until you feel sleepy.

In some cases, insomnia is caused by a medical condition such as sleep apnea, restless legs syndrome or chronic pain, or by a mental health disorder such as depression. Treatment for one of these underlying conditions may be necessary for insomnia to get better. Also, treating insomnia may help depression symptoms improve faster.

If you keep having sleep problems, talk to your doctor. To determine the cause and best treatment for insomnia, you may need to see a sleep specialist. Your doctor may prescribe medication and have you try other strategies to get your sleep pattern back on track. Depending on the cause of insomnia, a referral to a mental health professional may help some people.

Intermittent fasting means that you don't eat for a period of time each day or week. Some popular approaches to intermittent fasting include:

• Alternate-day fasting. Eat a normal diet one day and either completely fast or have one small meal (less than 500 calories) the next day.
• 5:2 fasting. Eat a normal diet five days a week and fast two days a week.
• Daily time-restricted fasting. Eat normally but only within an eight-hour window each day. For example, skip breakfast but eat lunch around noon and dinner by 8 p.m.

Some studies suggest that alternate-day fasting is about as effective as a typical low-calorie diet for weight loss. That seems reasonable because reducing the number of calories you eat should help you lose weight.

Can intermittent fasting improve your health? Losing weight and being physically active help lower your risk of obesity-related diseases, such as diabetes, sleep apnea and some types of cancer. For these diseases, intermittent fasting seems to be about as beneficial as any other type of diet that reduces overall calories.

Some research suggests that intermittent fasting may be more beneficial than other diets for reducing inflammation and improving conditions associated with inflammation, such as:

• Alzheimer's disease
• Arthritis
• Asthma
• Multiple sclerosis
• Stroke

It's important to note that intermittent fasting can have unpleasant side effects, but they usually go away within a month. Side effects may include:

• Hunger
• Fatigue
• Insomnia
• Nausea
• Headaches

Intermittent fasting is safe for many people, but it's not for everyone. Skipping meals may not be the best way to manage your weight if you're pregnant or breast-feeding. If you have kidney stones, gastroesophageal reflux, diabetes or other medical problems, talk with your doctor before starting intermittent fasting.

Inversion therapy doesn't provide lasting relief from back pain, and it's not safe for everyone. Inversion therapy involves hanging upside down, and the head-down position could be risky for anyone with high blood pressure, heart disease or glaucoma.

In theory, inversion therapy takes gravitational pressure off the nerve roots and disks in your spine and increases the space between vertebrae. Inversion therapy is one example of the many ways in which stretching the spine (spinal traction) has been used in an attempt to relieve back pain.

Well-designed studies evaluating spinal traction have found the technique ineffective for long-term relief. However, some people find traction temporarily helpful as part of a more comprehensive treatment program for lower back pain caused by spinal disk compression.

Your heartbeat slows and your blood pressure increases when you remain inverted for more than a couple of minutes — and the pressure within your eyeballs jumps dramatically. For these reasons, you should not try inversion therapy if you have high blood pressure, heart disease or glaucoma.

Home sperm tests measure sperm count — the number of sperm in the fluid (semen) ejaculated during an orgasm. But sperm count is only one factor in male fertility.

Home sperm tests require ejaculation into a collection cup. While procedures vary for transferring semen and completing the test, results are typically available within a few minutes. The tests work by detecting a protein found only in sperm. If a home sperm test indicates that your sperm concentration is low (negative), you'll likely want to consult a doctor for a complete fertility evaluation. A positive test result indicates that your sperm concentration is considered normal.

A normal sperm count, however, doesn't tell you whether you're fertile or not. Home sperm tests only determine sperm concentration. They don't measure any other factors. Many common causes of male infertility are missed by at-home sperm tests. A typical semen analysis performed by an infertility specialist assesses:

• Semen volume
• Total sperm number
• Sperm concentration
• Vitality (percent alive)
• Movement (motility)
• Shape (morphology)

If you're concerned about your fertility, get an infertility evaluation. Relying on a home sperm test might lead to delays in seeking appropriate fertility evaluation and treatment.

Rheumatoid arthritis and depression commonly occur together. Although this is known, people with rheumatoid arthritis often aren't screened for depression, so it may not be diagnosed or treated. Studies show that if depression occurring with rheumatoid arthritis isn't addressed, the treatment for rheumatoid arthritis itself can be less effective.

It's unclear whether depression and anxiety in people with rheumatoid arthritis are a result of their physical symptoms, or if depression is yet another symptom caused by the chronic, systemic inflammation of rheumatoid arthritis.

Researchers believe that people who had depression before the onset of rheumatoid arthritis may be less responsive to their rheumatoid arthritis treatment. More research is needed to determine the exact connection between all types of arthritis and depression. Left untreated, depression in people with rheumatoid arthritis may result in:

• Greater pain
• Greater risk of cardiovascular disease and heart attacks
• Loss of productivity at work
• Increased risk of economic hardship
• Deterioration of relationships with friends and family
• Sexual dysfunction

What is known is that people who have rheumatoid arthritis and depression that occur together respond better to treatment when both conditions are addressed.

Although different medications may be prescribed to treat rheumatoid arthritis and depression, many activities can be helpful in addressing the physical and emotional effects of both conditions, such as:

• Regular exercise
• Stress management techniques
• Friends and support groups familiar with the challenges of both conditions

People with all types of arthritis are at high risk of depression and anxiety. If you have been diagnosed with rheumatoid arthritis and are feeling depressed or are worried about developing depression, it's important to talk to your doctor. With medication, support and a personalized plan of action, depression and rheumatoid arthritis are treatable conditions.

Fibromyalgia isn't passed directly from parents to children, but the disorder does appear to cluster within families.

The odds of developing fibromyalgia are several times higher in the immediate families of people with fibromyalgia than in families in which no one has fibromyalgia.

In fact, studies of DNA from family members of people with fibromyalgia and other chronic pain syndromes have turned up a number of genes that could help explain why these disorders seem to run in families.

Each of these genes plays a role in your nervous system's response to pain. Some of the same genes are also associated with depression and anxiety, which may be the reason why certain antidepressant medications help reduce fibromyalgia symptoms.

A gluten-free diet is recommended for people with celiac disease, gluten-sensitivity or the skin disorder dermatitis herpetiformis. A gluten-free diet may be helpful for some people with irritable bowel syndrome, the neurological disorder gluten ataxia, type 1 diabetes and HIV-associated enteropathy.

Beyond this, there's little evidence that a gluten-free diet offers any particular health benefits. However, a gluten-free diet can still be a healthy way to eat depending on which gluten-free foods you choose, how often you eat them and whether your other food choices are healthy ones.

Good gluten-free choices include naturally gluten-free foods, such as lean meats, low-fat dairy, vegetables, fruit, whole gluten-free grains and healthy fats.

It's important not to replace gluten-containing foods with more red meat, full-fat dairy, starchy vegetables, sweets and fats, which can lead to a higher intake of cholesterol, saturated fat, sodium and unwanted calories.

It's also prudent to limit commercially prepared gluten-free snacks and bakery products, which are typically high in refined carbohydrate, fat, sugar and salt — just like their gluten-containing counterparts.

Studies suggest that the nutritional quality of commercially prepared gluten-free products varies from similar gluten-containing products. In several countries, for example, commercially prepared gluten-free foods are lower in protein than their conventional counterparts.

In the U.S., gluten-free foods tend to be lower in folate, thiamin, riboflavin and niacin. This may be because in this country most wheat products are enriched with folic acid, thiamin, riboflavin, niacin and iron, while gluten-free flours, cereals and bread products typically are not.

However, gluten-free whole grains, such as amaranth, quinoa, buckwheat, teff, millet, corn and rice, are good natural sources of folate, thiamin, riboflavin, niacin and iron — as well as protein and fiber.

It's probably safe to leave food in takeout containers. The key is to store food in a shallow container that can be sealed when the food has cooled. These practices help limit bacteria.

Here's another safety tip: Don't let prepared food sit out — in your car or on the counter — for more than two hours. If you're someplace hot, where the temperature is more than 90 F (32 C), reduce that time to one hour. Bacteria can grow rapidly in food that's unrefrigerated. And some bacteria make a poison (toxin) that can make you ill, hence the term "food poisoning."

If you don't plan on eating takeout food immediately, you have two choices. You can keep it hot — internal temperature of 140 F (60 C) or higher — in an ovenproof dish in a preheated oven. Or you can divide the food into smaller portions, place it in shallow containers and refrigerate. Plan to reheat the food to a temperature of 165 F (74 C) just before serving.

The National Institute on Aging and the Alzheimer's Association are suggesting changes to the research definition of Alzheimer's disease. There are new criteria to define what Alzheimer's disease is and who has it — but only as it relates to clinical trials and research, and not the diagnosis in your doctor's office.

Previously, Alzheimer's disease dementia was characterized by symptoms such as memory loss and changes in thinking and cognition. And that's still the case when your doctor diagnoses Alzheimer's disease dementia.

The proposed research definition of Alzheimer's is defined by the presence of biomarkers — a buildup of plaques and tangles in the brain — which are identified by imaging scans of the brain and samples of cerebrospinal fluid. This change allows researchers to better design clinical trials, include the right participants and learn more about the disease in its earlier stages.

Here's why it's important: The classic symptoms of Alzheimer's disease don't define or diagnose it. They're a complication of the changes in the brain that do define the disease — and these brain changes can occur long before the symptoms show up. This change in research may lead to earlier diagnosis of Alzheimer's disease, which will hopefully lead to delayed progression and better treatments.