Many people who have chronic low back pain have found acupuncture to be helpful. But the scientific evidence to support these claims has been mixed, partly because it can be difficult to devise a good form of sham acupuncture for comparison.

Acupuncture for back pain involves inserting very thin needles to various depths into strategic points on your body. Scientific studies have indicated that sham acupuncture works just as well as real acupuncture for back pain. A key point, though, is that in several studies, both sham acupuncture and real acupuncture relieved low back pain better than having no treatment at all.

This could mean that sham acupuncture — placing needles in locations not associated with traditional treatment points — could be having an effect, or it could mean that the effects of acupuncture may be due in part to a placebo effect.

The research on acupuncture is growing, but interpreting it is still a challenge. For now, most studies seem to indicate that, for most people, acupuncture results in some beneficial effect with a low risk of side effects when provided by a well-trained practitioner.

So if other treatments haven't helped your low back pain, it may be worth trying acupuncture. But if your back pain doesn't begin to improve within a few weeks, acupuncture may not be the right treatment for you.

Yes. Most of the time, acute bronchitis is caused by a virus, such as the flu (influenza) virus. However, many different viruses — all of which are very contagious — can cause acute bronchitis.

Viruses spread mainly from person to person by droplets produced when an ill person coughs, sneezes or talks and you inhale the droplets. Viruses may also spread through contact with an infected object. This happens when you touch something with the virus on it and then touch your mouth, eyes or nose.

To reduce your risk of catching viruses that can cause bronchitis:

• Avoid close contact with people who have the flu or another respiratory illness
• Wash your hands often or use an alcohol-based hand sanitizer
• Avoid touching your eyes, nose and mouth
• Get an annual flu shot

People who have chronic bronchitis or asthma sometimes develop acute bronchitis. In these cases, the acute bronchitis is most likely a complication of the existing condition. This type of bronchitis is not caused by an infectious virus, so it's less likely to be contagious.

Acute flaccid myelitis is a rare condition that affects the nerves in the spinal cord. It can cause sudden weakness in the arms or legs and other symptoms. It tends to happen mainly in children.

The condition may have various causes. Infection with viruses such as adenovirus, poliovirus, other enteroviruses and West Nile virus may precede it.

Acute flaccid myelitis may be treated by doctors trained in nervous system conditions (neurologists). Therapies specifically for acute flaccid myelitis aren't available, but doctors may suggest physical and occupational therapy to help improve weakness in the arms and legs.

To prevent acute flaccid myelitis, it may help to get your child vaccinated against poliovirus.

You can also help prevent the condition by limiting your child's chances of getting West Nile virus, which is spread through mosquito bites. Using mosquito repellent, avoiding being outdoors at dusk and dawn, and eliminating standing water on your property may protect your child from getting mosquito bites.

It may also help to use commonsense precautions to avoid catching illnesses — such as having your child regularly wash his or her hands with soap and water.

Acute hepatitis C infection doesn't always lead to chronic hepatitis C infection. But because a large majority of people with the acute infection go on to chronic infection, acute hepatitis C is serious.

Fortunately, acute hepatitis C can be treated, greatly reducing the risk of chronic infection. Unfortunately, acute hepatitis C usually causes no symptoms, so diagnosis and treatment rarely occur.

Acute hepatitis C develops two weeks to six months after the hepatitis C virus enters your bloodstream. In the small proportion of people who get sick during the acute infection, signs and symptoms include:

• Jaundice
• Dark urine
• White-colored stool
• Nausea
• Pain in the upper right part of the abdomen

These signs and symptoms last for two to 12 weeks.

Most acute hepatitis C infections today occur in people who share needles to inject drugs. Health care workers who have needle-stick injuries also are at risk.

If you think you've recently been exposed to the hepatitis C virus, it's important to get tested right away. Blood tests to detect hepatitis C virus proteins, followed by a later test to detect antibodies to the virus, can usually distinguish acute from chronic infection. Having an acute hepatitis C infection makes a difference in the choice of treatment.

Yes. Over-the-counter (OTC) pain relievers and decongestants may help relieve facial pain and sinus congestion associated with acute sinusitis.

OTC medications that may help include:

• Decongestants. These work by narrowing blood vessels to help reduce inflammation and swelling that cause sinus congestion. Such OTC medications (Sudafed, others) are available in liquids, tablets and nasal sprays.
• Pain relievers. Pain caused by pressure buildup in the sinus cavities may be relieved by pain relievers such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others).

Always use OTC products as directed. If your child becomes infected, check with his or her doctor to find out what's safe.

Other home remedies you may want to try:

• Inhale warm water vapor. Drape a towel over your head as you breathe in the moist air from a bowl of warm or moderately hot water. Or take a hot shower, breathing in the warm, moist air.
• Apply warm compresses. Place warm, damp towels around your nose, cheeks and eyes to ease facial pain.
• Drink plenty of fluids. Consuming additional fluids helps dilute mucous secretions and promotes drainage.
• Use a saline nasal spray. Saline washes or sprays can remove thick secretions and allow the sinuses to drain.
• Use a neti pot. A neti pot is a container designed to rinse debris or mucus from your nasal cavity. Neti pots are often available in pharmacies and health food stores, as well as online. Talk to your doctor to see if nasal rinsing is right for you.

Most people with acute sinusitis get better without antibiotics. However, if your symptoms are severe or last longer than a few days, talk to your doctor.

Food additives include artificial colors, artificial sweeteners and preservatives. There's no solid evidence that food additives cause attention-deficit/hyperactivity disorder (ADHD). However, the topic of food additives and their possible effects is controversial.

Some studies indicate that certain food colorings and preservatives may increase hyperactive behavior in some children. But the Food and Drug Administration (FDA) Food Advisory Committee determined that studies to date have not proved there's a link between food colorings and hyperactivity.

Countries differ on which food color additives, sometimes called food dyes, they'll allow in food and drinks and how they're labeled. For example, the European Union (EU) requires that foods containing certain food color additives include a statement on the label that this color "may have an adverse effect on activity and attention in children." The FDA only requires that FDA-certified color additives be listed on the food label.

Better research is needed to find out if limiting certain foods or food additives will help reduce hyperactivity and ADHD symptoms.

Talk with your child's doctor about the pros and cons of trying a diet that eliminates food additives to see if it makes a difference in your child's behavior. Make sure your doctor or a dietitian helps supervise the diet plan. A diet that eliminates too many foods can be unhealthy because it may lack necessary vitamins and nutrients.

The best approach for overall health and nutrition is a diet that limits sugary and processed foods and is rich in fruits, vegetables, grains, and healthy fats such as omega-3 fatty acids found in certain types of fish, flaxseed and other foods.

It's true the Adiana system for female sterilization isn't available anymore. The manufacturer stopped producing the Adiana system for financial reasons in 2012.

A type of permanent birth control for women, the Adiana system used low-level radiofrequency energy along with two small silicone pieces placed in each of the fallopian tubes. Scar tissue formed around the silicone inserts, blocking the fallopian tubes and preventing sperm from reaching an egg.

The Adiana system still provides permanent contraception for women who previously had the system placed in their fallopian tubes.

Adrenal fatigue isn't an accepted medical diagnosis. It is a lay term applied to a collection of nonspecific symptoms, such as body aches, fatigue, nervousness, sleep disturbances and digestive problems.

Your adrenal glands produce a variety of hormones that are essential to life. The medical term "adrenal insufficiency" refers to inadequate production of one or more of these hormones as a result of an underlying disease or surgery.

Signs and symptoms of adrenal insufficiency may include:

• Fatigue
• Body aches
• Unexplained weight loss
• Low blood pressure
• Lightheadedness
• Loss of body hair
• Skin discoloration (hyperpigmentation)

Adrenal insufficiency can be diagnosed by blood tests and special stimulation tests that show inadequate levels of adrenal hormones.

Proponents of the adrenal fatigue diagnosis claim this is a mild form of adrenal insufficiency caused by chronic stress. The unproven theory behind adrenal fatigue is that your adrenal glands are unable to keep pace with the demands of perpetual fight-or-flight arousal. Existing blood tests, according to this theory, aren't sensitive enough to detect such a small decline in adrenal function — but your body is.

It's frustrating to have persistent symptoms your doctor can't readily explain. But accepting a medically unrecognized diagnosis from an unqualified practitioner may leave the real cause — such as depression or fibromyalgia — undiagnosed, while it continues to take its toll.

Hormones likely play a role in the development of adult acne, but hormones generally aren't the root cause of acne.

It's true that some people with hormonal imbalances due to diseases such as polycystic ovary syndrome experience more problems with acne. However, most of those with adult acne have no measurable hormonal imbalance.

A number of so-called natural acne treatments promise to "equalize" hormonal imbalances to reduce adult acne breakouts. But "natural hormones" are often derived from plants. Their chemical structure is different from hormones produced in the body, so their effectiveness may be limited. And because hormonal imbalance isn't thought to play a major role in acne anyway, the premise behind such products is shaky at best.

Adult acne can be a distressing and frustrating problem. Successful treatment of severe adult acne may take months or even years. But the good news is that effective treatments are available. If you're concerned about adult acne, consult a dermatologist to learn more about safe, proven treatments. Also, check with your doctor before taking any dietary supplements, especially if you have any underlying health conditions.

Bed-wetting that starts in adulthood (secondary enuresis) is uncommon and requires medical evaluation.

Causes of adult bed-wetting may include:

• A blockage (obstruction) in part of the urinary tract, such as from a bladder stone or kidney stone
• Bladder problems, such as small capacity or overactive nerves
• Diabetes
• Enlarged prostate
• Medication side effect
• Neurological disorders
• Obstructive sleep apnea
• Urinary tract infection

Tests and procedures used to determine the cause of adult bed-wetting include:

• Physical exam
• Urine tests
• Urologic tests
• Neurological evaluation

Treatment of adult bed-wetting is directed at the underlying cause, when possible.